Several reports have described the poor quality of care delivered to psychotic patients. However, the context in which care was delivered, including the structure, organization, and performance of the health care system, as a possible determinant of quality of care has received less attention. In this study we explored the relationship between conformance with guidelines and structural and organizational characteristics in 2 departments of Mental Health in Italy. Dosing of antipsychotic drugs in the maintenance phase was investigated in 125 patients. Higher than recommended doses could be explained by the high patient caseload per psychiatrist, leading to insufficient contacts with patients and their families and to excessive reliance upon drug treatment. The analysis of structural and organizational determinants of care at the local level may help to explain insufficient quality and to plan suitable interventions.