The prevalence of T102C polymorphism of the 5-hydroxytryptamine 5-HT2a receptor gene has been investigated using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 80 Kuwaiti Arabs with schizophrenia and in 109 normal healthy controls with a similar ethnic background. There was no significant difference in the frequency of T102 polymorphism in the Kuwaiti cohort of schizophrenia patients and the controls (P = 0.23). The data from Kuwaiti Arabs (although our sample size is relatively small) support the findings from some other populations (Caucasians, Japanese), in which a lack of association has been found between T102C polymorphism and the onset of schizophrenia.