peer reviewed ; BACKGROUND: the objective of this study was twofold:1) Describe the use of antipsychotic treatments in ambulatory patients suffering from schizophrenia in Belgium.2) Evaluate to which extend antipsychotic treatment prescribing patterns are in accordance with published treatment guidelines. METHOD: A cross-sectional survey was carried out in 16 Belgian hospitals selected from a sample of 67 hospitals. The hospitals were equally distributed between the north and south part of the country and were representative of Belgian practice. During 2 months, participating psychiatrists were asked to record the medication use as well as demographic parameters of all consecutive ambulatory patients seen at their consultation or attending a day-hospital. Data concerning 1000 ambulatory patients with schizophrenia or schizoaffective disorder were collected. RESULTS: In Belgium, the use of atypical antipsychotics is frequent (69%) in ambulatory patients with schizophrenia. In the overall sample, 73% receive only one antipsychotic drug. The majority of patients are treated with drugs of only one antipsychotic drug group, either first- typical (29.8%) or second-generation, atypical antipsychotics (53.2%). 15.8% of patients combine different types of antipsychotics. Antipsychotic dosing is adequate for the majority of patients but about one fifth receives a higher than recommended dose as per package inserts. Polypharmacy remains within reasonable limits. The use of concomitant medication varies according the antipsychotic treatment: patients who take second-generation antipsychotics only, receive the least additional drugs. CONCLUSION: Atypical antipsychotics appear to be the first line treatment for schizophrenic psychosis. Psychiatrists working with ambulatory patients are well aware of treatment guidelines and follow them quite adequately.