The women's 4 × 100 metre medley relay competition at the 1999 Pan Pacific Swimming Championships took place on August 29 at the Sydney International Aquatic Centre. The last champion was the United States. Records Prior to this competition, the existing world and Pan Pacific records were as follows: Results All times are in minutes and seconds. Heats Heats weren't performed, as only seven teams had entered. Final The final was held on August 29. References 4 × 100 metre freestyle relay 1999 Pan Pacific Swimming Championships 1999 in women's swimming