diff --git a/internal/lsp/imports.go b/internal/lsp/imports.go
new file mode 100644
index 00000000000..c3ecc132e13
--- /dev/null
+++ b/internal/lsp/imports.go
@@ -0,0 +1,34 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lsp
+
+import (
+	"context"
+
+	"golang.org/x/tools/internal/lsp/cache"
+	"golang.org/x/tools/internal/lsp/protocol"
+	"golang.org/x/tools/internal/lsp/source"
+)
+
+func organizeImports(ctx context.Context, v *cache.View, uri protocol.DocumentURI) ([]protocol.TextEdit, error) {
+	f := v.GetFile(source.URI(uri))
+	tok, err := f.GetToken()
+	if err != nil {
+		return nil, err
+	}
+	r := source.Range{
+		Start: tok.Pos(0),
+		End:   tok.Pos(tok.Size()),
+	}
+	content, err := f.Read()
+	if err != nil {
+		return nil, err
+	}
+	edits, err := source.Imports(ctx, tok.Name(), content, r)
+	if err != nil {
+		return nil, err
+	}
+	return toProtocolEdits(tok, content, edits), nil
+}
diff --git a/internal/lsp/server.go b/internal/lsp/server.go
index 21941d5c63f..cc10074930f 100644
--- a/internal/lsp/server.go
+++ b/internal/lsp/server.go
@@ -56,6 +56,7 @@ func (s *server) Initialize(ctx context.Context, params *protocol.InitializePara
 
 	return &protocol.InitializeResult{
 		Capabilities: protocol.ServerCapabilities{
+			CodeActionProvider: true,
 			CompletionProvider: protocol.CompletionOptions{
 				TriggerCharacters: []string{"."},
 			},
@@ -250,8 +251,22 @@ func (s *server) DocumentSymbol(context.Context, *protocol.DocumentSymbolParams)
 	return nil, notImplemented("DocumentSymbol")
 }
 
-func (s *server) CodeAction(context.Context, *protocol.CodeActionParams) ([]protocol.CodeAction, error) {
-	return nil, notImplemented("CodeAction")
+func (s *server) CodeAction(ctx context.Context, params *protocol.CodeActionParams) ([]protocol.CodeAction, error) {
+	edits, err := organizeImports(ctx, s.view, params.TextDocument.URI)
+	if err != nil {
+		return nil, err
+	}
+	return []protocol.CodeAction{
+		{
+			Title: "Organize Imports",
+			Kind:  protocol.SourceOrganizeImports,
+			Edit: protocol.WorkspaceEdit{
+				Changes: map[protocol.DocumentURI][]protocol.TextEdit{
+					params.TextDocument.URI: edits,
+				},
+			},
+		},
+	}, nil
 }
 
 func (s *server) CodeLens(context.Context, *protocol.CodeLensParams) ([]protocol.CodeLens, error) {
diff --git a/internal/lsp/source/format.go b/internal/lsp/source/format.go
index 2f9938f63a7..0ac932a00de 100644
--- a/internal/lsp/source/format.go
+++ b/internal/lsp/source/format.go
@@ -13,9 +13,10 @@ import (
 	"go/format"
 
 	"golang.org/x/tools/go/ast/astutil"
+	"golang.org/x/tools/imports"
 )
 
-// Format formats a document with a given range.
+// Format formats a file with a given range.
 func Format(ctx context.Context, f File, rng Range) ([]TextEdit, error) {
 	fAST, err := f.GetAST()
 	if err != nil {
@@ -54,11 +55,24 @@ func Format(ctx context.Context, f File, rng Range) ([]TextEdit, error) {
 	if err := format.Node(buf, fset, node); err != nil {
 		return nil, err
 	}
-	// TODO(rstambler): Compute text edits instead of replacing whole file.
+	return computeTextEdits(rng, buf.String()), nil
+}
+
+// Imports formats a file using the goimports tool.
+func Imports(ctx context.Context, filename string, content []byte, rng Range) ([]TextEdit, error) {
+	content, err := imports.Process(filename, content, nil)
+	if err != nil {
+		return nil, err
+	}
+	return computeTextEdits(rng, string(content)), nil
+}
+
+// TODO(rstambler): Compute text edits instead of replacing whole file.
+func computeTextEdits(rng Range, content string) []TextEdit {
 	return []TextEdit{
 		{
 			Range:   rng,
-			NewText: buf.String(),
+			NewText: content,
 		},
-	}, nil
+	}
 }