diff --git a/dvc/command/diff.py b/dvc/command/diff.py
index 026ea1372..42113f900 100644
--- a/dvc/command/diff.py
+++ b/dvc/command/diff.py
@@ -72,9 +72,7 @@ class CmdDiff(CmdBase):
 
     def run(self):
         try:
-            diff = self.repo.diff(
-                self.args.a_ref, self.args.b_ref, target=self.args.target
-            )
+            diff = self.repo.diff(self.args.a_ref, self.args.b_ref)
 
             if not any(diff.values()):
                 return 0
@@ -124,15 +122,6 @@ def add_parser(subparsers, parent_parser):
         ),
         nargs="?",
     )
-    diff_parser.add_argument(
-        "-t",
-        "--target",
-        help=(
-            "Source path to a data file or directory. Default None. "
-            "If not specified, compares all files and directories "
-            "that are under DVC control in the current working space."
-        ),
-    )
     diff_parser.add_argument(
         "--show-json",
         help="Format the output into a JSON",
diff --git a/dvc/repo/diff.py b/dvc/repo/diff.py
index 89676f24b..1945bd1f5 100644
--- a/dvc/repo/diff.py
+++ b/dvc/repo/diff.py
@@ -46,12 +46,10 @@ def _diffables_from_output(output):
 
 
 @locked
-def diff(self, a_ref="HEAD", b_ref=None, *, target=None):
+def diff(self, a_ref="HEAD", b_ref=None):
     """
     By default, it compares the working tree with the last commit's tree.
 
-    When a `target` path is given, it only shows that file's comparison.
-
     This implementation differs from `git diff` since DVC doesn't have
     the concept of `index`, but it keeps the same interface, thus,
     `dvc diff` would be the same as `dvc diff HEAD`.
@@ -67,7 +65,6 @@ def diff(self, a_ref="HEAD", b_ref=None, *, target=None):
             for stage in self.stages
             for out in stage.outs
             for diffable in _diffables_from_output(out)
-            if not target or target == str(out)
         )
 
     old = outs[a_ref]
diff --git a/scripts/completion/dvc.bash b/scripts/completion/dvc.bash
index b64839029..8c2d3b061 100644
--- a/scripts/completion/dvc.bash
+++ b/scripts/completion/dvc.bash
@@ -22,7 +22,7 @@ _dvc_checkout='-d --with-deps -R --recursive -f --force --relink $(compgen -G *.
 _dvc_commit='-f --force -d --with-deps -R --recursive $(compgen -G *.dvc)'
 _dvc_config='-u --unset --local --system --global'
 _dvc_destroy='-f --force'
-_dvc_diff='-t --target --show-json --checksums'
+_dvc_diff='-t --show-json --checksums'
 _dvc_fetch='-j --jobs -r --remote -a --all-branches -T --all-tags -d --with-deps -R --recursive $(compgen -G *.dvc)'
 _dvc_get_url=''
 _dvc_get='-o --out --rev --show-url'
diff --git a/scripts/completion/dvc.zsh b/scripts/completion/dvc.zsh
index 08ed4f607..03f9fa69c 100644
--- a/scripts/completion/dvc.zsh
+++ b/scripts/completion/dvc.zsh
@@ -97,7 +97,6 @@ _dvc_destroy=(
 )
 
 _dvc_diff=(
-  {-t,--target}"[Source path to a data file or directory.]:Target files:"
   "--show-json[Format the output into a JSON]"
   "--checksums[Display checksums for each entry]"
   {1,2}":Git revision (e.g. branch, tag, SHA):"
diff --git a/tests/func/test_diff.py b/tests/func/test_diff.py
index 1ffb1c699..caaa7e074 100644
--- a/tests/func/test_diff.py
+++ b/tests/func/test_diff.py
@@ -111,35 +111,6 @@ def test_refs(tmp_dir, scm, dvc):
         dvc.diff("missing")
 
 
-def test_target(tmp_dir, scm, dvc):
-    tmp_dir.dvc_gen("foo", "foo")
-    tmp_dir.dvc_gen("bar", "bar")
-    scm.add([".gitignore", "foo.dvc", "bar.dvc"])
-    scm.commit("lowercase")
-
-    tmp_dir.dvc_gen("foo", "FOO")
-    tmp_dir.dvc_gen("bar", "BAR")
-    scm.add(["foo.dvc", "bar.dvc"])
-    scm.commit("uppercase")
-
-    assert dvc.diff("HEAD~1", target="foo") == {
-        "added": [],
-        "deleted": [],
-        "modified": [
-            {
-                "filename": "foo",
-                "checksum": {"old": digest("foo"), "new": digest("FOO")},
-            }
-        ],
-    }
-
-    assert dvc.diff("HEAD~1", target="missing") == {
-        "added": [],
-        "deleted": [],
-        "modified": [],
-    }
-
-
 def test_directories(tmp_dir, scm, dvc):
     tmp_dir.dvc_gen({"dir": {"1": "1", "2": "2"}}, commit="add a directory")
     tmp_dir.dvc_gen({"dir": {"3": "3"}}, commit="add a file")