Assessed prevalence of anxiety and depression in patients coming to primary care centers in Riyadh, to determine the proportion of missed cases, and to obtain some descriptive sociodemographic information on the patients concerned. The 411 Ss (aged 16-65 yrs) were patients who came to selected primary health care centers for the 1st time during the index period. Patients completed the Arabic version of the Hospital Anxiety and Depression (HAD) scale and a personal data form. Physicians completed a form after the doctor-patient encounter requiring a "Yes" or "No" response for the presence of depression and/or anxiety without references to the HAD scores. The primary care physicians in the study failed to detect anxiety and/or depression in many of the patients. The HAD appears to be a reliable instrument for screening for clinically significant anxiety and depression in patients attending a general medical clinic.