Some studies on discharge against medical advice (AMA) in general hospitals report a prevalence between 0.7–7% with 11–42% of this population identified as psychiatric patients. To study the sociodemographic and psychopathological features of patients who leave AMA, we performed a retrospective case-control comparison study of length of hospitalization and presence of psychiatric disturbances on patients who left AMA from the University General Hospital in Catalan Spain over a two-year period. An analysis of the hospital epidemiological discharge register and retrospective chart review for presence of psychiatric disturbances found that AMA prevalence was 0.34%, the total discharge number in the 2-year period being 41,648. AMA rates by medical department were 0.44% for the internal medicine department; 0.24% for surgery; 0.26% for orthopedic surgery, 0.32% for obstetrics–gynecology and 0.93% for rehabilitation. The mean age for AMA patients was 38.63 years, with a higher number of men (59.9%). A total of 45.8% AMA discharges were from the internal medicine department. No significant differences were found in the average length of hospitalization between the AMA and control groups. The presence of psychiatric pathology was significantly higher among the AMA group (P<.05). The prevalence of AMA at our hospital was low in comparison to the rates reported in the literature. The patient at high risk for AMA discharge is a young man with a history of psychiatric pathology, mainly narcotic dependence. [Copyright &y& Elsevier]