The adverse, short-term effects of postpartum depression on maternal-infant interaction have been repeatedly documented. Are there long-term sequelae for children whose mothers had experienced postpartum depression? The purpose of this meta-analysis was to determine the magnitude of the effect of postpartum depression on the cognitive and emotional development of children older than the age of 1 year. Nine studies which met the sample criteria were included in this meta-analysis. Results indicated that postpartum depression had a small but significant effect on children's cognitive and emotional development. The r indicator for effect size ranged from .18 to .22 whereas the d indicator ranged from .36 to .45. Implications for future research are addressed.