Background: Postnatal depression has received considerable research and clinical attention, however anxiety and stress in the postpartum has been relatively ignored. Along with the widespread use of the Edinburgh Postnatal Depression Scale (EPDS), depression has become the marker for postnatal maladjustment. Symptoms of anxiety tend to be subsumed within diagnoses of depression, which can result in anxiety being minimized or overlooked in the absence of depression. Some researchers have identified the need to distinguish between postnatal depression and anxiety, and to discern cases where depression and anxiety co-exist. The aim of this study was to assess the prevalence of postnatal distress using the EPDS and the Depression Anxiety Stress Scales (DASS-21). Method: As part of a larger cross-sectional study, the EPDS and DASS-21 were administered to a convenience sample of 325 primiparous mothers, who ranged in age from 18 to 44 years (M = 32 years). Recruited through mother's groups and health centres in Melbourne Australia, inclusion was limited to mothers whose babies were aged between 6 weeks and 6 months. Analyses included comparisons between the classifications of women according to the EPDS and the DASS-21, and an exploration of the extent to which the EPDS identified anxious-depressed women. Results: The EPDS identified 80 women (25%) as possibly depressed (using a cut-off of over 9), of which the DASS-21 corroborated 58%. In the total sample, 61 women (19%) were classified by the DASS-21 to be depressed. Using broader criteria for distress, it was revealed by the DASS-21 that a further 33 women (10%) showed symptoms of anxiety and stress without depression. A total of 41 women (13%) had symptoms of anxiety either in isolation or in combination with depression. The DASS-21 identified 7% of the sample as being both anxious and depressed. This at-risk subgroup had higher mean EPDS and DASS-depression scores than their depressed-only counterparts. Conclusion: The prevalence of anxiety and stress in the present study points to the importance of assessing postnatal women for broader indicators of psychological morbidity than that of depression alone. The DASS-21 appears to be a useful instrument for this purpose.