Job-related burnout is an occupational hazard for health care professionals. This study aimed to determine the prevalence of burnout and its associated factors among physicians working at primary health care centres in Asir province, Saudi Arabia. In a cross-sectional survey applying the Maslach Burnout Inventory (MBI) with standard cut-offs, 29.5% of respondents reported high emotional exhaustion, 15.7% high depersonalization and 19.7% low personal accomplishment, with 6.3% scoring high in all 3 dimensions. High emotional exhaustion score was associated with younger age, Saudi nationality and salary 15 000–20 000 SR. Physicians who had more working days and those who had longer duration of annual vacation were less likely to report emotional exhaustion. High depersonalization score was associated with Saudi nationality, working for 5–15 years and salary > 20 000 SR. Low personal accomplishment score was associated with younger age, non-Saudi nationality, working for ≥ 5 years and more annual vacation.