We sought to determine whether postcaesarean treatment with whey peptides (WP) affects the healing of skin and uterine incision in rats during puerperium. Forty-eight rats were randomly divided into two groups. After a caesarean section, twenty-four rats were intragastrically administered WP, while others were administered a control vehicle. On days 7, 14 and 21 after delivery, the serum total protein/albumin concentration, skin tensile strength, uterine bursting pressure, skin/uterine hydroxyproline (Hyp) concentration and histological characteristics of the scar were measured in eight rats in each group. In the WP group, the albumin concentration, skin tensile strength, uterine bursting pressure and Hyp concentration in the skin increased significantly on days 21, 7, 14 and 21, respectively. Low neutrophil count and smaller scar width in the skin incision were found in the WP group on day 7. Postcaesarean treatment with WP promoted significant wound healing in the skin incision, and had a significant wound healing potential in the uterus.