OBJECTIVES: To describe real life disease characteristics, side effects and socioeconomic situations for schizophrenia inpatients and outpatients treated with olanzapine or haloperidol over 12 months. METHODS: GEO is a German 2-year prospective naturalistic observational study. Quarterly observations were made for 289 patients included in the study under olanzapine treatment and 187 patients included under haloperidol treatment. RESULTS: During the 12 months study period, olanzapine and haloperidol treatment was stable (olanzapine: 96% of follow up days with study medication coverage vs. haloperidol: 94%; medication or dosage changes 56% vs. 38%). General, negative and cognitive symptoms ranged from ‘moderate’ to ‘clearly ill’ (average CGI summary scores 3 – 4). Positive and depressive symptoms ranged from ‘mild’ to ‘moderate’ (CGI 2 – 3). During the course of the study, disease severity improved for all symptoms (p<0.05; not significant for haloperidol positive and depressive score) with slightly better improvement in olanzapine patients. Throughout the study period, significantly fewer olanzapine patients had extrapyramidal side effects. Average extrapyramidal, parkinsonism, retardation and akathisia side effects were milder in olanzapine patients. Other side effects were reported more frequently for olanzapine (<28% vs. < 8%). Concomitant schizophrenia-related medication was prescribed significantly less frequently for olanzapine patients (48% vs. 64%). Compared to haloperidol patients, more patients under olanzapine were able to care for themselves (86% vs. 79%), lived at home without care (58% vs. 39%), were employed (34% vs. 17%), and fewer were in early retirement (29% vs. 49%). CONCLUSIONS: In Germany, real life schizophrenia patients under olanzapine treatment showed a higher degree of integration into social and occupational environment. For olanzapine patients, all schizophrenia symptoms significantly improved over time. Additionally, olanzapine patients exhibited less extrapyramidal, parkinsonism, retardation and akathisia side-effects than patients treated with haloperidol.