diff --git a/lib/db/schema.rb b/lib/db/schema.rb
index 30117de..2627e18 100644
--- a/lib/db/schema.rb
+++ b/lib/db/schema.rb
@@ -20,6 +20,7 @@ def write(*args)
           t.string  :class_type, null: false
           t.text    :parameters      # JSON string of method parameters
           t.boolean :class_method, default: false # true for class methods (def self.method)
+          t.text    :included_modules # JSON array of included module names
         end
 
         add_index :scopes, :name
diff --git a/lib/ruby_language_server/completion.rb b/lib/ruby_language_server/completion.rb
index 972b137..7dd5564 100644
--- a/lib/ruby_language_server/completion.rb
+++ b/lib/ruby_language_server/completion.rb
@@ -153,6 +153,13 @@ def scope_completions(word, scopes)
 
         scope_ids = scopes.map(&:id)
         word_scopes = scopes.to_a + RubyLanguageServer::ScopeData::Scope.where(parent_id: scope_ids).closest_to(word).limit(5)
+
+        # Add methods from included modules
+        scopes.each do |scope|
+          included_module_scopes = get_included_module_scopes(scope)
+          word_scopes += included_module_scopes
+        end
+
         scope_words = word_scopes.select(&:named_scope?).sort_by(&:depth).map { |scope| [scope.name, scope] }
         variable_words = RubyLanguageServer::ScopeData::Variable.where(scope_id: scope_ids).closest_to(word).limit(5).map { |variable| [variable.name, variable.scope] }
         words = (scope_words + variable_words).to_h
@@ -164,6 +171,41 @@ def scope_completions(word, scopes)
           hash[w][:parameters] = scope.parsed_parameters if scope.method? && scope.parameters.present?
         end
       end
+
+      # Get all scopes from included modules
+      def get_included_module_scopes(scope)
+        included_scopes = []
+        module_names = scope.parsed_included_modules
+
+        module_names.each do |module_name|
+          # Try to find the module by full path first
+          full_module_path = resolve_module_path(module_name, scope)
+          module_scope = RubyLanguageServer::ScopeData::Scope.find_by(path: full_module_path, class_type: RubyLanguageServer::ScopeData::Base::TYPE_MODULE)
+
+          # If not found by full path, try searching by name
+          module_scope ||= RubyLanguageServer::ScopeData::Scope.where(name: module_name, class_type: RubyLanguageServer::ScopeData::Base::TYPE_MODULE).first
+
+          if module_scope
+            # Get all methods defined in the module
+            included_scopes += module_scope.children.where(class_type: RubyLanguageServer::ScopeData::Base::TYPE_METHOD).to_a
+          end
+        end
+
+        included_scopes
+      end
+
+      # Resolve the full module path considering the current scope
+      def resolve_module_path(module_name, scope)
+        # If it starts with ::, it's an absolute path
+        return module_name.sub(/^::/, '') if module_name.start_with?('::')
+
+        # Try to resolve relative to current scope
+        if scope.parent && scope.parent.path.present?
+          "#{scope.parent.path}::#{module_name}"
+        else
+          module_name
+        end
+      end
     end
   end
 end
diff --git a/lib/ruby_language_server/scope_data/scope.rb b/lib/ruby_language_server/scope_data/scope.rb
index 09a7b33..18d09c0 100644
--- a/lib/ruby_language_server/scope_data/scope.rb
+++ b/lib/ruby_language_server/scope_data/scope.rb
@@ -94,6 +94,22 @@ def set_parameters(params_array)
         self.parameters = params_array.to_json if params_array.present?
       end
 
+      # Get included modules as an array of strings
+      def parsed_included_modules
+        return [] unless included_modules.present?
+
+        JSON.parse(included_modules)
+      rescue JSON::ParserError
+        []
+      end
+
+      # Add an included module name
+      def add_included_module(module_name)
+        current = parsed_included_modules
+        current << module_name unless current.include?(module_name)
+        self.included_modules = current.to_json
+      end
+
       # Called from ScopeParser to cleanup empty blocks.
       def close
         destroy! if block_scope? && variables.none?
diff --git a/lib/ruby_language_server/scope_parser_commands/ruby_commands.rb b/lib/ruby_language_server/scope_parser_commands/ruby_commands.rb
index 70b7944..3a20e48 100644
--- a/lib/ruby_language_server/scope_parser_commands/ruby_commands.rb
+++ b/lib/ruby_language_server/scope_parser_commands/ruby_commands.rb
@@ -41,6 +41,15 @@ def on_attr_writer_command(line, args, rest)
         ruby_command_add_attr(line, column, names, false, true)
       end
 
+      def on_include_command(_line, _args, rest)
+        # Extract the module name(s) from the include statement
+        module_names = rest.flatten.select { |o| o.instance_of? String }
+        module_names.each do |module_name|
+          @current_scope.add_included_module(module_name)
+          @current_scope.save!
+        end
+      end
+
       private
 
       def ruby_command_names(rest)
diff --git a/spec/lib/ruby_language_server/completion_spec.rb b/spec/lib/ruby_language_server/completion_spec.rb
index 3c99201..0960758 100644
--- a/spec/lib/ruby_language_server/completion_spec.rb
+++ b/spec/lib/ruby_language_server/completion_spec.rb
@@ -194,4 +194,69 @@ def method_mixed(required, optional = nil, *rest, keyword:, **kwargs, &block)
       assert_equal('arg1 (required), arg2 (required)', simple_method_item[:detail], 'should include parameter details')
     end
   end
+
+  describe 'module inclusion' do
+    before do
+      @code_with_include = <<-SOURCE
+      module FooModule
+        def foo_method
+        end
+
+        def another_foo_method(param1)
+        end
+      end
+
+      class BarClass
+        include FooModule
+
+        def bar_method
+          foo # completion should find foo_method from included FooModule module
+        end
+      end
+      SOURCE
+      @include_parser = RubyLanguageServer::ScopeParser.new(@code_with_include)
+    end
+
+    it 'should track included modules in scope' do
+      all_scopes = @include_parser.root_scope.self_and_descendants
+      bar_class = all_scopes.find_by_path('BarClass')
+
+      assert bar_class, 'BarClass should exist'
+      included_modules = bar_class.parsed_included_modules
+      assert_equal(['FooModule'], included_modules, 'BarClass should have FooModule in its included modules')
+    end
+
+    it 'should include methods from included modules in completions' do
+      all_scopes = @include_parser.root_scope.self_and_descendants
+      bar_method_scope = all_scopes.find_by_path('BarClass#bar_method')
+
+      assert bar_method_scope, 'bar_method scope should exist'
+
+      # Get completions for 'foo' prefix within BarClass#bar_method
+      context = ['foo']
+      position_scopes = @include_parser.root_scope.self_and_descendants.for_line(bar_method_scope.top_line + 1)
+      completions = scope_completions(context.last, position_scopes)
+
+      # Should include foo_method from the included FooModule module
+      completion_names = completions.map(&:first)
+      assert_includes(completion_names, 'foo_method', 'Should find foo_method from included module FooModule')
+      assert_includes(completion_names, 'another_foo_method', 'Should find another_foo_method from included module FooModule')
+    end
+
+    it 'should include method parameters from included modules' do
+      all_scopes = @include_parser.root_scope.self_and_descendants
+      bar_method_scope = all_scopes.find_by_path('BarClass#bar_method')
+
+      # Get completions for 'another_foo' prefix
+      context = ['another_foo']
+      completions = RubyLanguageServer::Completion.completion(context, bar_method_scope, all_scopes)
+
+      # Find the another_foo_method completion
+      another_foo_item = completions[:items].find { |item| item[:label].start_with?('another_foo_method') }
+
+      assert another_foo_item, 'another_foo_method should be in completions'
+      assert_equal('another_foo_method(param1)', another_foo_item[:label], 'should include parameters in label')
+      assert_equal('another_foo_method(${1:param1})', another_foo_item[:insertText], 'should include parameter snippet')
+    end
+  end
 end