Family violence (FV) has serious effects on the health and well-being of the family. The health sector plays a vital role in FV prevention by helping to identify abuse early, providing victims with the necessary treatment and referring patients to appropriate care. The aim of the present cross-sectional study was to describe the prevalence of FV among hospital patients, as well as to assess the association between family functioning, health and social support, considering patients as the perpetrators or victims of violence. The data were collected using a Family Functioning, Health and Social Support (FAFHES) questionnaire that was given to patients who visited a Finnish central hospital between October 2012 and April 2013. As a result, the data (N = 188) were contributed by the patients who returned the questionnaire and gave permission for a follow-up survey. The participation rate was 47%, of which 73% were women and 27% were men. Their ages ranged from 18 to 89 years. The data were analysed with quantitative methods using the unadjusted analyses and linear regression model. In total, 24% of both the male and female participants had experienced or used violence at home or in the family. Of these, 22 had been the perpetrators, and 23 had been the victims. Participants in relationships and who were living together had less violence than singles and those who were not living together. The family functioning and health of the participants who had experienced or used FV were worse than those of the participants who had not. Various patients can have an FV background, and nursing professionals are on the front line to identify and intervene in FV situations. The results of this study can be utilised in the treatment of FV victims and perpetrators by training healthcare workers to identify and intervene in violence.