Additional evidence for a role of serotonin (5-HT) in the pathogenesis of suicidal behavior is provided by a recent report that the 5-HT2A (HTR2A) T102C polymorphism was associated with suicidality in patients with major depression. Three other studies have, however, failed to find an association between this polymorphism and suicidality in major depression. The goal of the present study was to test the association of allele C of T102C HTR2A polymorphism with suicidality in patients with schizophrenia or schizoaffective disorder. Seventy-one patients with DSM-III-R diagnosis of schizophrenia or schizoaffective disorder were included in the study. Patients were genotyped for the T102C HTR2A polymorphism. Information about lifetime suicidality was obtained during the course of SADS interviews. In addition, current suicidality was assessed by the Hamilton Depression Scale in 46 patients. There were no significant differences in allele frequencies and genotype distributions between suicidal and non-suicidal patients using lifetime or current suicidality measures. The results of this study did not demonstrate a robust association of the allele C of the T102C HTR2A polymorphism with lifetime or current suicidality in patients with schizophrenia. However, the mean Hamilton Depression Scale item for current suicidality was significantly higher in patient with genotype T/C compared to those with genotype C/C (p = 0.01) and marginally higher than for the patients with genotype T/T (p=0.06). The relatively small sample size suggests a study with a larger sample and greater power would be of interest.