The development, reliability, and validity of a new instrument designed to assess aspects of social support specifically relevant to the postpartum period, the Postpartum Social Support Questionnaire (PSSQ), is described. The PSSQ was administered to 126 women at 2, 4, 6, and 12 months postpartum. Results indicate that it has high test-retest reliability and internal consistency. Factor analyses suggest that the scale consists of four factors: partner support, parent support, in-law support, and extended-family and friends support. In addition, the PSSQ scores of depressed and nondepressed women were compared at 2, 4, 6, and 12 months postpartum. Women who met diagnostic criteria for depression at 2 months postpartum reported less partner support than the nondepressed women at each assessment. The instrument appears to be a valid and reliable measure that should be useful in studies examining the role of social support in postpartum adaptation.