diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 5d3c632872..5edac4d267 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -26,7 +26,8 @@ OPTIONS
 --tool=<tool>::
 	Use the merge resolution program specified by <tool>.
 	Valid merge tools are:
-	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge, and opendiff
+	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge,
+	tortoisemerge and opendiff
 +
 If a merge resolution program is not specified, 'git-mergetool'
 will use the configuration variable `merge.tool`.  If the
diff --git a/Documentation/merge-config.txt b/Documentation/merge-config.txt
index 9c44af8e4a..8c10f66702 100644
--- a/Documentation/merge-config.txt
+++ b/Documentation/merge-config.txt
@@ -23,7 +23,7 @@ merge.tool::
 	Controls which merge resolution program is used by
 	linkgit:git-mergetool[1].  Valid built-in values are: "kdiff3",
 	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff",
-	"ecmerge" and
+	"ecmerge", tortoisemerge and
 	"opendiff".  Any other value is treated is custom merge tool
 	and there must be a corresponding mergetool.<tool>.cmd option.
 
diff --git a/git-mergetool.sh b/git-mergetool.sh
index 6e611e94a4..be9717a2f1 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -265,6 +265,16 @@ merge_file () {
 	    fi
 	    status=$?
 	    ;;
+	tortoisemerge)
+	    if base_present ; then
+		touch "$BACKUP"
+		"$merge_tool_path" -base:"$BASE" -mine:"$LOCAL" -theirs:"$REMOTE" -merged:"$MERGED"
+		check_unchanged
+	    else
+		echo "TortoiseMerge cannot be used without a base" 1>&2
+		status=1
+	    fi
+	    ;;
 	*)
 	    if test -n "$merge_tool_cmd"; then
 		if test "$merge_tool_trust_exit_code" = "false"; then
@@ -345,7 +355,7 @@ valid_custom_tool()
 
 valid_tool() {
 	case "$1" in
-		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
+		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge | tortoisemerge)
 			;; # happy
 		*)
 			if ! valid_custom_tool "$1"; then
@@ -404,9 +414,9 @@ fi
 if test -z "$merge_tool" ; then
     if test -n "$DISPLAY"; then
         if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-            merge_tool_candidates="meld kdiff3 tkdiff xxdiff gvimdiff"
+            merge_tool_candidates="meld kdiff3 tkdiff xxdiff tortoisemerge gvimdiff"
         else
-            merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
+            merge_tool_candidates="kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff"
         fi
     fi
     if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then