The women's 4 × 100 metre medley relay competition at the 2010 Pan Pacific Swimming Championships took place on August 21 at the William Woollett Jr. Aquatics Center.[1][2] The last champion was the United States.[3][4]
Prior to this competition, the existing world and Pan Pacific records were as follows:
All times are in minutes and seconds.
Heats weren't performed, as only four teams had entered.
The final was held on August 21, at 20:15.[1]