OBJECTIVES: To describe real life disease characteristics, clinical status and socioeconomics for schizophrenia in- and outpatients treated with olanzapine or haloperidol over 24 months. METHODS: GEO is a two-year prospective naturalistic study in Germany. Quarterly observations were made for 308 patients under olanzapine treatment and 188 patients under haloperidol treatment. RESULTS: Compared to haloperidol patients, more patients included into the study under olanzapine lived at home without care (59% vs. 39%), were employed (35% vs. 17%), and fewer were in early retirement (30% vs. 51%). During the observational period, olanzapine and haloperidol treatment was stable (olanzapine: 94% retention vs. haloperidol: 92%; dosage changes occurred in 64% vs. 47%, respectively). Concomitant medication related to schizophrenia was prescribed less frequently for olanzapine patients (52% vs. 68%). Mean disease severity, negative and cognitive symptoms as assessed by CGI (scales from no symptoms (one) to very severe (seven)) ranged between three and four. Positive and depressive symptom values were lower (mean value between two and three). During the course of the study disease severity improved for all symptoms with slightly more improvement in olanzapine patients (mean change in disease severity: olanzapine 0.95; haloperidol 0.76). Throughout the 24-month period, olanzapine patients had lower average EPS, parkinsonism, retardation, dyskinesia and akathisia symptom scores (none (1) to severe (6)) than haloperidol patients (mean EPS: olanzapine 1.3; haloperidol 2.0). Weight gain, depression and other symptoms were reported more frequently for olanzapine (<28% vs. < 11%). Nevertheless, olanzapine patients showed a lower mean Body Mass Index (BMI) than haloperidol patients throughout the 24-month study period. CONCLUSIONS: Schizophrenia patients under olanzapine treatment showed a higher degree of integration into social and occupational environment. For olanzapine patients, all schizophrenia symptoms improved over time. Throughout the study, olanzapine patients exhibited less EPS and had a lower BMI.