diff --git a/changelog/fix_revert_flash_before_render.md b/changelog/fix_revert_flash_before_render.md
new file mode 100644
index 0000000000..f2409cd09a
--- /dev/null
+++ b/changelog/fix_revert_flash_before_render.md
@@ -0,0 +1 @@
+* [#1269](https://github.com/rubocop/rubocop-rails/issues/1269): Fix positives for `Rails/ActionControllerFlashBeforeRender` in combination with implicit returns. ([@earlopain][])
diff --git a/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb b/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb
index 4704d07a29..e3eb5ba1e8 100644
--- a/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb
+++ b/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb
@@ -328,4 +328,71 @@ def create
       RUBY
     end
   end
+
+  context 'when using `flash` after `render` and `redirect_to` is used in implicit return branch ' \
+          'and render is is used in the other branch' do
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
+        class HomeController < ApplicationController
+          def create
+            if foo.update(params)
+              flash[:success] = 'msg'
+
+              if redirect_to_index?
+                redirect_to index
+              else
+                redirect_to path(foo)
+              end
+            else
+              flash.now[:alert] = 'msg'
+              render :edit, status: :unprocessable_entity
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when using `flash` after `render` and `render` is part of a different preceeding branch' \
+          'that implicitly returns' do
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
+        class HomeController < ApplicationController
+          def create
+            if remote_request? || sandbox?
+              if current_user.nil?
+                render :index
+              else
+                head :forbidden
+              end
+            elsif current_user.nil?
+              redirect_to sign_in_path
+            else
+              flash[:alert] = 'msg'
+              if request.referer.present?
+                redirect_to(request.referer)
+              else
+                redirect_to(root_path)
+              end
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when using `flash` in `rescue` and `redirect_to` in `ensure`' do
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
+        class HomeController < ApplicationController
+          def create
+          rescue
+            flash[:alert] = 'msg'
+          ensure
+            redirect_to :index
+          end
+        end
+      RUBY
+    end
+  end
 end