Self-efficacy and family social support are significantly associated with hypertension self-care behaviours. However, little is known about their mechanism in Saudi Arabia. This cross-sectional study aimed to examine the relationships among family social support, self-efficacy, and self-care behaviours among men with hypertension in Saudi Arabia.Data were collected from May to August of 2018. The Hypertension Self-Care Profile and the Perceived Social Support from Friends and Family scales were used to measure the study variables. Multiple linear regression was used to analyse the relationships between the variables, and the Baron and Kenny test was used to assess if self-efficacy mediated the relationship between family social support and hypertension self-care behaviours.Respondents (N = 158) from the Jizan and Al-Sharqia regions of Saudi Arabia completed the survey. Family social support and self-efficacy were significantly associated with hypertension self-care behaviours. In regression, self-efficacy was the only variable significantly associated with hypertension self-care behaviours. Self-efficacy fully mediated the relationship between family social support and hypertension self-care behaviours.Interventions to enhance hypertension self-care behaviours among Saudi men could focus on increasing individual's self-confidence to perform specific healthy behaviours. Family support can also contribute to the performance of hypertension self-care behaviours.