Several studies have suggested that there is a substantial genetic contribution to suicidal behavior. Genes encoding proteins involved in serotonergic transmission are major candidates in association studies of suicidal behavior. In this study, we aimed to investigate the 5-HT2A receptor (5HTR2A) and tryptophan hydroxylase (TPH) genes for association with suicidal behavior in depressive patients.Patients with major depression who had recently attempted suicide (n=191) and control subjects (n=193) were genotyped for 5HTR2A 102T/C, and TPH 218A/C. The lethality of the suicide attempt was measured using the Risk-Rescue Rating (RRR) and Lethality Suicide Attempt Rating Scale (LSARS). The severity of depression was measured using the Hamilton Depression Rating Scale (HDRS).There were no significant differences in the genotype distributions or allelic frequencies in the two serotonergic polymorphisms between suicide attempters and normal controls. None of the two serotonergic polymorphisms was correlated with lethality.We concluded that these polymorphisms may not be associated with susceptibility to suicidal behavior in our Korean population. Our results were in line with most previous studies. More work is needed to replicate these findings. Our future studies aim at identifying other genetic associations.