The mental state of 20 consecutive hemodialysis patients investigated at a Nigerian renal unit was assessed using the 30-item General Health Questionnaire, Present State Examination, and clinical evaluation using the Diagnostic and Statistical Manual, revised third edition (DSM-III-R). Findings were compared with those of orthopedic patients and apparently healthy controls. A standard interview was used in eliciting sociodemographic data from the subjects. A significantly higher prevalence of psychiatric disorders was identified in hemodialysis patients (55%) than in orthopedic patients (20%) and apparently healthy controls (0%). The psychiatric disorders encountered in this hemodialysis population included major depressive episode (35%) and generalized anxiety disorder (20%). The probable reasons for the higher prevalence of psychiatric morbidity in this hemodialysis population, compared with those in Western societies, are discussed. Psychiatric morbidity was higher in patients with low levels of education, and did not show statistically significant relationship with other sociodemographic variables.