Background & objectives: Plasma leptin level during pregnancy has been reported as a biochemical predictor of postpartum weight retention. The objective of this study was to determine the relationship between pregnancy-related factors including plasma leptin and postpartum weight retention in Korean women. Methods: A convenience sampling method was used among women attending a high-risk pregnancy clinic in Pusan National University Hospital, Busan, between March 2002 and February 2003. We investigated 75 women during pregnancy and 6 months postpartum. Plasma leptin levels were measured using an ELISA. The weight gain during pregnancy and postpartum weight retention, and the correlation between the plasma leptin levels and body weight were evaluated.