A functional polymorphism in the promoter region of the dopamine D2 receptor gene, the -141C Del allele, which may be associated with schizophrenia susceptibility, has previously been described in a Japanese sample. The present study was done in order to examine whether such an association would also be found in a North American schizophrenia patient population. However, analysis of the -141C Del allele frequency in the present group of schizophrenia patients (n = 50) and control subjects (n = 51) did not identify any significant differences. These data support the recent reports on German and British subjects that this genetic variation in the 5'-flanking region of the dopamine D2 receptor gene does not play a major role in the genetic predisposition to schizophrenia.