When people in Sweden are sentenced and handed over to forensic psychiatric care(FPC), the authorities have overall responsibility for their health recovery. How nursing staff construct gender through their relations in this context affects their understanding of health promotion activities. The aim of this study was to illuminate, using a gender perspective, the understanding of nursing staff with respect to health promotion activities for patients. Four focus group interviews were conducted with nursing staff in two FPC clinics in Sweden. The study has a qualitative inductive design with an ethnographic approach. This study sheds new light on FPC in which its dual goals of protecting society and providing care are viewed from a gender perspective. When relationships within the nursing staff group and the nurse–patient relationship are justified by the goal of protecting society, gender becomes invisible.This might cause patients' individual conditions and needs for certain types of activitiesto go unnoticed. One of the implications of ignoring gender relations in nursingstaff health promotion activities is that it risks contributing to gender stereotypes which impact on the nurse–patient relationship and the quality of care.