P is a licensed physician practicing cosmetic surgery in the State of Hawaii. P filed for bankruptcy after a jury awarded a former patient $2 million in her malpractice suit against him. On June 10, 1996, P filed a complaint against D, the Hawaii Plastic Surgery Society, the American Society of Plastic and Reconstructive Surgeons, Inc., seven individual plastic surgeons, and two professional medical corporations. P alleged unfair competition, unlawful restraint of trade, and various antitrust violations. On October 4, 1996, P filed an amended complaint, pursuant to Fed. R. Civ. P. 15(a), naming an additional defendant, the American Board of Medical Specialties. D was served with both the original and amended complaints on October 28, 1996, 20 days after the expiration of the original 120-day period provided for under Rule 4(m). P failed to serve D during the 120-day period because counsel had used that time to make his Rule 11 inquiry, concluding by October 4, 1996, that a factual and legal basis for suit existed. Service had been initially mailed to D on October 4, 1996, it was directed to William D. Morain, M.D., who was no longer employed by D. CP re-served D on October 24, 1996. This time, service was directed to Constance Hanson, an administrator, who accepted it on October 28, 1996. On January 17, 1997, D moved to dismiss under Rules 12(b)(2) and 12(b)(3) asserting that Hawaii lacked personal jurisdiction over it and that venue was improper. d did not allege a defect in the October 28 service of process pursuant to Rules 12(b)(4) or 12(b)(5). P re-serving D under the Clayton Act. P believed that the October 4 filing of the first amended complaint initiated a new 120-day time period in which to serve D, but even that period would have expired on February 3, 1997. On February 5, 1997, McCurdy filed an ex parte motion requesting the court to exercise its discretion under Fed. R. Civ. P. 4(m) to extend the 120-day period by nine days. On February 7, 1997, the amended complaint was personally served on D under the nationwide service provision of the Clayton Act. The Hawaii magistrate judge denied without prejudice P's ex parte motion to enlarge the time in which to serve. On February 27, 1997, D moved to quash the February 7, 1997 service on the ground that it was untimely under Rule 4(m). On April 11, 1997, the court ruled that it lacked personal jurisdiction over D and that venue was improper. It transferred the suit to Pennsylvania 'in the interest of justice,' as it would have otherwise been time-barred as of that time. P never re-served D. On May 13, 1997, D filed a motion to dismiss arguing that the original October 28, 1996, service was untimely. P claimed D had waived any challenges to timeliness because its motion to dismiss the action in the District of Hawaii listed as grounds only the lack of personal jurisdiction and venue. The Pennsylvania district court granted D's motion because it read Rule 4(m) which requires that service of process be made within 120 days to be mandatory, and not subject to waiver. It found that P had not been diligent in attempting to serve D and declined to find good cause for extending the time for service. The district court dismissed the complaint and P appealed. P claims that D waived any challenge to the October 28 service by not raising it in the Rule 12 motion filed in Hawaii on January 17, 1997.