The Edinburgh Postnatal Depression Scale (EPDS) was designed to be used by community health workers to screen for postnatal depression. We report data from a population-based sample of 1655 women who completed the EPDS at 2 months and 3 months postpartum. A total of 128 women were interviewed with the Montgomery Asberg Depression Rating Scale (MADRS) and assessed according to DSM-III-R criteria for major depression. A cut-off score of 11.5 on the EPDS identified all but two women with major depression, giving it a sensitivity of 96%, a specificity of 49% and a positive predictive value of 59%. This study supports the validity of the EPDS shown in earlier studies, and indicates that the scale is a useful screening instrument for identifying postnatal depression in primary health care in Sweden.