Social workers who are based in hospitals regularly participate in on-call services whereby they respond to crisis or emergency presentations outside of usual working hours. A social work research team across four metropolitan hospitals in a Local Heath District in Sydney, Australia, investigated the experience of participating in an on-call service and the impact this had on the wellbeing of the social workers involved. By utilising a Participatory Action Research methodology that included in-depth interviews and reflective co-analysis, the findings showed evidence of risk for on-call social workers, as well as two key protective factors that mitigate the anxiety associated with night time and crisis work. These factors are preparation for participation in an on-call service, and timely and effective support whilst working outside of normal working hours. This research offers suggested strategies for translation into other hospital social work departments who undertake on-call services.