This paper presents the results of a 12-week pilot project that studied the demand for and utility of an out-of-hours on-call psychiatric service delivered by two experienced psychiatric nurses in an A&E department. It also considers some of the implications for a possible permanent, substantive service. An initiative to reduce the on-call hours worked by junior medical staff harked back to literature which has long suggested that health professionals, other than medical staff, can competently perform risk assessments and determine the immediate needs of patients who self-harm. The project's aims were to determine: (i) whether an on-call psychiatric nurse could satisfactorily reduce the pressures on on-call junior doctors; and (ii) the absolute demand for and nature of requested out-of-hours psychiatric assistance. Summarized details of referred patients include data on time and duration of contact, reasons for referral, outcome and other professionals involved. Of the 88 patients referred during the pilot period, 33 (37.5% of the total) were admitted to psychiatric wards and four to medical wards. Although a range of professionals was needed during the 12-week period, the nurses dealt with 42 (47.7%) of the referrals without any other professional involvement.