The present study investigates whether the history of gestational diabetes mellitus (GDM) influences self-efficacy and coping among postpartum women. Purposive sanding technique was used to collect data from 100 postpartum women, 50 with a history of GDM and 50 without. The General Perceived Self-Efficacy Scale was used to measure the self-efficacy of the participants. The Brief COPE developed by Carver was used to measure coping. A Mann-Whitney U-test showed postpartum women with a history of GDM are higher in self-efficacy and coping than those without such a history. Even though self-efficacy showed a relationship to coping, the two groups differed in the use of coping strategies.