BACKGROUND : There is a paucity of economic studies carried out in the routine clinical practice of psychiatric services. This study estimated service and non-service costs in a random sample of patients attending a community psychiatric mental health centre in Italy. Costs of different diagnostic subgroups and variables associated with service and non-service costs were calculated. METHODS : A randomly selected sample of patients identified during one week of routine clinical activity was enrolled. Information was collected using the Italian-language checklist Questionario Economico per l’attività clinica dei Servizi Psichiatrici (QESP). Costs were classified in two categories: service costs (from the provision of services) and non-service costs (loss of productivity and informal care). RESULTS : One hundred and twenty patients were included. In patients suffering from schizophrenia the monthly service cost per patient was nearly double that for patients with other diagnoses. Non-service costs associated with patients’ lack of job opportunities were more than three times higher for patients with schizophrenia, accounting for a total monthly non-service cost per patient more than three times higher than that for patients with other diagnoses. Non-service costs associated with patients’ and caregivers’ time off work were similar in the two groups. In the multivariate analysis being unemployed was associated with higher service costs. Younger age, length of illness and diagnosis of schizophrenia were determinants of higher non-service costs. The latter three independent variables were also associated with overall (service and non-service) costs. CONCLUSION : The present study estimated service and non-service costs under routine circumstances to provide information on costs that community psychiatric services, patients and care-givers sustain when dealing with psychiatric problems.