Temple v. Synthes Corp. 498 U.S. 5, 111 S. Ct. 315, 112 L. Ed.2d 263 (1990) Temple lived in Mississippi. He had back surgery in Louisiana performed by LaRocca. LaRocca used surgical screws made by Synthes, which was a Pennsylvania corporation. The screws broke and Temple was injured. He sued Synthes in Federal Court under diversity jurisdiction. At the same time he sued LaRocca (and the hospital) in Louisiana State Court. Synthes argued that under Rule 19, Temple was required to join LaRocca into the Federal lawsuit. Synthes could have also attempted to join LaRocca into the Federal lawsuit themselves by using Rule 14(a). The Federal Trial Court ordered Temple to join LaRocca as a co-defendant or risk dismissal. When he failed to do so, the Court dismissed the case. Temple appealed. The Federal Appellate Court affirmed. The Federal Appellate Court found that the claims overlapped and it would be prejudicial to try the cases separately. Synthes was going to blame LaRocca and LaRocca was going to blame Synthes. The US Supreme Court reversed and remanded for trial. The US Supreme Court found that it is not necessary for all joint tortfeasors to be named as defendants in a single lawsuit. Basically, although it would be efficient and convenient to have a single lawsuit, LaRocca was not an indispensable party. You could proceed with each lawsuit independently. Rule 19 is for situations such as where the decision of the court might require binding of a party who was not in the court. In this case, no verdict against Synthes could possibly bind LaRocca to anything, so there is no requirement for joining. LaRocca and Synthes are permissive parties. See Haas v. Jefferson National Bank (442 F.2d 394 (1971)) for an example of where Rule 19 is required. Btw, the Supreme Court issued this unanimous opinion solely on the basis of the petition for certiorari. They were so sure of the answer, they didn't bother to schedule an oral argument or get a briefing on the merits.