The association between suicide and a single nucleotide polymorphism (rs1386483) was examined in the recently identified tryptophan hydroxylase 2 (TPH2) gene. Blood samples of 143 suicide victims and 162 age- and sex-matched controls were examined. The frequency of the TT genotype in the TPH2 polymorphism was higher in suicide victims than in controls (17.5% vs. 8.6%; p = 0.02), particularly in those with a history of repeated suicide attempts (53.3% vs. 8.6%; p less than 0.0001). The examined "TPH2" polymorphism was found to be associated with suicide. This genetic marker may be particularly important in understanding risk of multiple suicide attempts. Further analyses are needed to confirm these results. (Contains 3 tables.)