Objective: The developments experienced in the treatment of schizophrenia has increased the number of antiphyschotic drugs and thus treatment options of the clinicians accordingly, but this increaseas caused difficulties in the decision making process regarding treatment protocols. In this retrospective study, it is aimed to determine the frequency of the combined antipsychotic treatments among inpatients in Samsun Mental Hospital and which medicine combinations are used. Method: We evaluated the files of the patients who diagnosed as schizophrenia and schizoaffective disorder according to DSM-IV diagnostic criteria. The combined medicine prescription is the least two antiphyschotic drugs together for four weeks in treatment doses. Results: We examined 1001 hospitalization files of 867 patients file who were diagnosed as schizophrenia and schizoaffective disorders. For 383 hospitalizations (38,26%) at least two antiphyschotic drugs were given together for at least four weeks in treatment dose. At each hospitalization average of 1,38 antiphyschotic drug was used for at least four weeks in effective treatment dose whereas average of 1,98 antiphyschotatic drug was used for at least one week in any dose. More than one antiphyschotic was used in 41 different combinations in 1001 hospitalizations. The used combinations were respectively first generation- second generation combination (56,92%), first generationfirst generation combination (24, 54%) and second generation-second generation combination (18, 53%). Conclusion: In this study has been shown that the majority of the inpatients (%38,26) has received combined antiphyschotic drug in treatment dose, but this rate was not significantly different than the rates specified in the literature.