                   FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

SCOTT M. WILLIAMS, an individual         
and all others similarly situated,
                   Plaintiff-Appellee,
                  v.                         No. 03-56093
COSTCO WHOLESALE CORPORATION,                  D.C. No.
a Washington corporation, dba               CV-02-02003-
Costco,                                        NAJ/JFS
               Defendant-Appellant,           OPINION
                 and
DOES 1-150, inclusive,
                         Defendants.
                                         
        Appeal from the United States District Court
          for the Southern District of California
        Napoleon A. Jones, District Judge, Presiding

                  Argued and Submitted
           August 16, 2006—Pasadena, California

                   Filed December 6, 2006

    Before: Alex Kozinski, Diarmuid F. O’Scannlain and
               Jay S. Bybee, Circuit Judges.

                     Per Curiam Opinion




                             19213
             WILLIAMS v. COSTCO WHOLESALE CORP.            19215


                          COUNSEL

Kenwood C. Youmans, David D. Kadue & Thomas J.
Wybenga, Seyfarth Shaw LLP, Los Angeles, California, for
the appellant.

Frank J. Coughlin, Coughlin & Conforti, Santa Ana, Califor-
nia; Earl R. Wallace, Ruzicka, Snyder & Wallace, LLP, New-
port Beach, California, for the respondent.


                          OPINION

PER CURIAM:

   Williams sued Costco in California state court, alleging
violations of federal and state law. Costco properly removed
the case to district court, relying on federal question jurisdic-
tion. After removal, Williams amended his complaint to elim-
19216           WILLIAMS v. COSTCO WHOLESALE CORP.
inate the only federal claim and to add new state law claims.
He then filed a motion to remand. The district court held that
it had discretion to remand the state law claims, and did so.

   At the time Williams filed his motion to remand, however,
the district court had jurisdiction over the remaining state law
claims based on diversity of citizenship. The district court rec-
ognized this,1 but held that Costco could not rely on this
ground because it had not filed a second removal notice
within 30 days of the amended complaint—the document that
had first made it clear that the requirements for diversity were
satisfied.2

   [1] The district court erred.3 We have long held that post-
removal amendments to the pleadings cannot affect whether
a case is removable, because the propriety of removal is deter-
mined solely on the basis of the pleadings filed in state court.
  1
     The district court seems to have believed that William’s original com-
plaint, the one filed in state court, was unclear as to whether the amount
in controversy exceeded $75,000, but the amended complaint cured this
uncertainty. We have some doubt that the original complaint failed to
clearly allege the jurisdictional amount, but it makes no difference. If the
original complaint in fact supported federal jurisdiction on both diversity
and federal question grounds, Costco was not required to list both grounds
in its notice of removal. The civil removal statute, unlike the removal stat-
ute for criminal cases, has no requirement that all grounds for removal be
listed in the notice. Compare 28 U.S.C. § 1446(b) with id. § 1446(c)(2).
And, if the original complaint already stated a claim for diversity of citi-
zenship, the question that distracted the district court—i.e., whether
Costco was required to file a second notice of removal—is rendered moot.
   2
     The district court derived the 30-day time-limit from the second para-
graph of 28 U.S.C. § 1446(b), which deals with the situation where the
grounds for removal are not apparent from the original state-court plead-
ing, but become apparent upon the filing of an amended pleading or other
paper. In such circumstances a defendant has 30 days from service of this
document to file a notice of removal.
   3
     Because this remand was not based on lack of subject matter jurisdic-
tion or any defect in the removal—the grounds for which 28 U.S.C.
§ 1447(d) bars appellate review—we may review the remand order. See
Quackenbush v. Allstate Ins. Co., 517 U.S. 706, 711-12 (1996).
                WILLIAMS v. COSTCO WHOLESALE CORP.                     19217
See Sparta Surgical Corp. v. Nat’l Ass’n of Sec. Dealers, Inc.,
159 F.3d 1209, 1213 (9th Cir. 1998); O’Halloran v. Univ. of
Wash., 856 F.2d 1375, 1379 (9th Cir. 1988). It follows that a
party that has properly removed a case need not amend its
removal notice or file a new notice after an amended com-
plaint changes the ground for federal jurisdiction. Because
post-removal pleadings have no bearing on whether the
removal was proper, there is nothing a defendant can or need
do to perfect the removal. See Yarnevic v. Brinks, Inc., 102
F.3d 753, 755 (4th Cir. 1996). Indeed, the idea of filing a
notice of removal in a case that is already pending in federal
court, having been properly removed, is nonsensical. After all,
“a Supplemental Notice of Removal would, if granted, have
the effect of removing a case that has already been removed.”
Nolan v. Boeing Co., 715 F. Supp. 152, 153 n.1 (E.D. La.
1989).

   [2] Once a case has been properly removed, the district
court has jurisdiction over it on all grounds apparent from the
complaint, not just those cited in the removal notice. See
Brockman v. Merabank, 40 F.3d 1013, 1016 (9th Cir. 1994).
Any post-removal pleadings must be treated just as they
would be in a case originally filed in federal court. Here, the
district court had authority over the state law claims in the
original complaint only on the basis of supplemental jurisdic-
tion. See 28 U.S.C. § 1367. Dismissal of the federal claim
would thus, ordinarily, have authorized the district court to
remand the pendent state law claims. Id. § 1367(c)(3). But, as
defendant pointed out below, the amended complaint pres-
ented an independent jurisdictional basis for the state law
claims, namely diversity. With rare exceptions not applicable
here,4 where the district court is presented with a case within
its original jurisdiction, it has “a ‘virtually unflagging obliga-
tion’ to exercise the jurisdiction conferred upon [it] by the
  4
   Neither plaintiff nor the district court has suggested that this is the rare
case where abstention may be appropriate. See Quackenbush, 517 U.S. at
716-17.
19218       WILLIAMS v. COSTCO WHOLESALE CORP.
coordinate branches of government and duly invoked by liti-
gants.” United States v. Rubenstein, 971 F.2d 288, 293 (9th
Cir. 1992) (quoting Colo. River Water Conservation Dist. v.
United States, 424 U.S. 800, 817 (1976)). The district court
had no discretion to remand these claims to state court.

  REVERSED.
