To develop a self-report questionnaire to measure the beliefs of Arabic primary care patients about the causes of their physical symptoms; to use this to quantify the beliefs of patients consulting their general practitioners (GPs) in Saudi Arabia; and to test whether patients with psychological problems differ from others in their beliefs, particularly religious and supernatural beliefs. Consecutive patients (N = 224) completed a specially developed aetiological beliefs' questionnaire. Patients were divided into two groups (cases and non-cases of emotional disorder) according to the GHQ-12. Religious and supernatural aspects of culture colour patients' symptom beliefs: that their symptoms were a test or punishment from Allah' was the most common belief. Even in non-cases, around half the patients also endorsed nerves and stress as a cause of their physical symptoms. Cases were more likely than non-cases to endorse items related to both religious and psychological factors. There is no support for the view that Saudi Arabian patients explain symptoms supernaturally as a way of denying psychological factors. GPs and health professionals in Saudi primary care need to understand what patients believe to be the cause of their problems and to appreciate that religious and psychological beliefs are both very common. GPs should address psychological beliefs and concerns even with those patients who present physical symptoms.