diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index e44a4988b7a..15d6711d467 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -23,7 +23,7 @@ SYNOPSIS
 	   [-A <post-context>] [-B <pre-context>] [-C <context>]
 	   [-f <file>] [-e] <pattern>
 	   [--and|--or|--not|(|)|-e <pattern>...]
-	   [--cached | --no-index | <tree>...]
+	   [ [--exclude-standard] [--cached | --no-index | --untracked] | <tree>...]
 	   [--] [<pathspec>...]
 
 DESCRIPTION
@@ -49,7 +49,20 @@ OPTIONS
 	blobs registered in the index file.
 
 --no-index::
-	Search files in the current directory, not just those tracked by git.
+	Search files in the current directory that is not managed by git.
+
+--untracked::
+	In addition to searching in the tracked files in the working
+	tree, search also in untracked files.
+
+--no-exclude-standard::
+	Also search in ignored files by not honoring the `.gitignore`
+	mechanism. Only useful with `--untracked`.
+
+--exclude-standard::
+	Do not pay attention to ignored files specified via the	`.gitignore`
+	mechanism.  Only useful when searching files in the current directory
+	with `--no-index`.
 
 -a::
 --text::
diff --git a/builtin/grep.c b/builtin/grep.c
index 1c359c26715..5e6d3c33522 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -637,13 +637,15 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 	return hit;
 }
 
-static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec)
+static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
+			  int exc_std)
 {
 	struct dir_struct dir;
 	int i, hit = 0;
 
 	memset(&dir, 0, sizeof(dir));
-	setup_standard_excludes(&dir);
+	if (exc_std)
+		setup_standard_excludes(&dir);
 
 	fill_directory(&dir, pathspec->raw);
 	for (i = 0; i < dir.nr; i++) {
@@ -750,7 +752,7 @@ static int help_callback(const struct option *opt, const char *arg, int unset)
 int cmd_grep(int argc, const char **argv, const char *prefix)
 {
 	int hit = 0;
-	int cached = 0;
+	int cached = 0, untracked = 0, opt_exclude = -1;
 	int seen_dashdash = 0;
 	int external_grep_allowed__ignored;
 	const char *show_in_pager = NULL, *default_pager = "dummy";
@@ -774,8 +776,13 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOLEAN(0, "cached", &cached,
 			"search in index instead of in the work tree"),
-		OPT_BOOLEAN(0, "index", &use_index,
-			"--no-index finds in contents not managed by git"),
+		{ OPTION_BOOLEAN, 0, "index", &use_index, NULL,
+			"finds in contents not managed by git",
+			PARSE_OPT_NOARG | PARSE_OPT_NEGHELP },
+		OPT_BOOLEAN(0, "untracked", &untracked,
+			"search in both tracked and untracked files"),
+		OPT_SET_INT(0, "exclude-standard", &opt_exclude,
+			    "search also in ignored files", 1),
 		OPT_GROUP(""),
 		OPT_BOOLEAN('v', "invert-match", &opt.invert,
 			"show non-matching lines"),
@@ -1045,13 +1052,16 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	if (!show_in_pager)
 		setup_pager();
 
+	if (!use_index && (untracked || cached))
+		die(_("--cached or --untracked cannot be used with --no-index."));
 
-	if (!use_index) {
-		if (cached)
-			die(_("--cached cannot be used with --no-index."));
+	if (!use_index || untracked) {
+		int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 		if (list.nr)
-			die(_("--no-index cannot be used with revs."));
-		hit = grep_directory(&opt, &pathspec);
+			die(_("--no-index or --untracked cannot be used with revs."));
+		hit = grep_directory(&opt, &pathspec, use_exclude);
+	} else if (0 <= opt_exclude) {
+		die(_("--exclude or --no-exclude cannot be used for tracked contents."));
 	} else if (!list.nr) {
 		if (!cached)
 			setup_work_tree();
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 0d600163c82..81263b78516 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -554,7 +554,6 @@ test_expect_success 'outside of git repository' '
 	mkdir -p non/git/sub &&
 	echo hello >non/git/file1 &&
 	echo world >non/git/sub/file2 &&
-	echo ".*o*" >non/git/.gitignore &&
 	{
 		echo file1:hello &&
 		echo sub/file2:world
@@ -571,6 +570,23 @@ test_expect_success 'outside of git repository' '
 		test_must_fail git grep o &&
 		git grep --no-index o >../../actual.sub &&
 		test_cmp ../../expect.sub ../../actual.sub
+	) &&
+
+	echo ".*o*" >non/git/.gitignore &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non/git" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+		test_must_fail git grep o &&
+		git grep --no-index --exclude-standard o >../actual.full &&
+		test_cmp ../expect.full ../actual.full &&
+
+		{
+			echo ".gitignore:.*o*"
+			cat ../expect.full
+		} >../expect.with.ignored &&
+		git grep --no-index --no-exclude o >../actual.full &&
+		test_cmp ../expect.with.ignored ../actual.full
 	)
 '
 
@@ -583,6 +599,10 @@ test_expect_success 'inside git repository but with --no-index' '
 	{
 		echo file1:hello &&
 		echo sub/file2:world
+	} >is/expect.unignored &&
+	{
+		echo ".gitignore:.*o*" &&
+		cat is/expect.unignored
 	} >is/expect.full &&
 	: >is/expect.empty &&
 	echo file2:world >is/expect.sub &&
@@ -591,12 +611,24 @@ test_expect_success 'inside git repository but with --no-index' '
 		git init &&
 		test_must_fail git grep o >../actual.full &&
 		test_cmp ../expect.empty ../actual.full &&
+
+		git grep --untracked o >../actual.unignored &&
+		test_cmp ../expect.unignored ../actual.unignored &&
+
 		git grep --no-index o >../actual.full &&
 		test_cmp ../expect.full ../actual.full &&
+
+		git grep --no-index --exclude-standard o >../actual.unignored &&
+		test_cmp ../expect.unignored ../actual.unignored &&
+
 		cd sub &&
 		test_must_fail git grep o >../../actual.sub &&
 		test_cmp ../../expect.empty ../../actual.sub &&
+
 		git grep --no-index o >../../actual.sub &&
+		test_cmp ../../expect.sub ../../actual.sub &&
+
+		git grep --untracked o >../../actual.sub &&
 		test_cmp ../../expect.sub ../../actual.sub
 	)
 '