Boklage's report of increased non-right handedness among monozygotic twins with schizophrenia has been cited as evidence to support an association of abnormal brain lateralization with the development of schizophrenia. The present study found no such association. Two previous attempts to replicate Boklage's findings (Luchins et al. 1980; Lewis et al. 1989) also reported little support. Studies of twin handedness do not appear to support an association of brain lateralization and schizophrenia.