The genetically determined CYP2D6 activity may be considered to be associated with antipsychotic induced extrapyramidal side effects with interindividual variation. Genetic polymorphism of CYP2D6 was determined by polymerase chain reaction(PCR) and MspI restriction fragment length polymorphisms(RFLP) for 194 schizophrenics. Subjects with a 334bp band were classified a1a1, those with 229bp and 105bp bands a2a2, and those with all three bands a1-a2. We did not identify schizophrenic subject with poor metabolizer. 194 schizophrenic patients previously treated neuroleptic medication, were assessed by Extrapyramidal Symptom Rating Scale(ESRS).The cases were composed of 33 akathisia, 47 parkinsonism, 21 tardive dyskinesia. These results are similar to the previous understanding that the poor metabolizer is very rare in Orientals compared to Caucasians, therefore, it considered that CYP2D6 genotypes have maybe no association with schizophrenia and extrapyramidal side effects in Koreans.