Reducing occupational stress among nursing staff is a public health priority in many western countries. This study assessed stress differentials between psychiatric nurses (PNs) and general nurses (GNs), and the moderating function of social support. It was expected that PNs would report different (higher) stress levels than GNs given PNs' lower levels of social support. A questionnaire was completed and returned by 73 nurses at several public hospitals in England. Multivariate analysis of variance showed that social support moderated stress differentials between PNs and GNs, albeit not as anticipated; the latter group reported significantly higher and lower stress levels when social support was low and high, respectively. This interaction was applicable to both the quality and quantity of social support. Overall, the benefits of social support seemed to accrue primarily to GNs. Implications of these findings for the development of stress-reduction interventions are considered.