Suicidal behavior runs in families and is partially genetically determined. Since greater serotonin 5-HT 2A receptor binding has been reported in postmortem brain and platelets of suicide victims, the 5-HT 2A receptor gene polymorphism T102C became one of the candidate sites in the study of suicide and impulsive-aggressive traits. However, studies that examined the association of this polymorphism with suicidality have contradictory results. This study used a family-based method and one homogenous ethnic group to overcome ethnic stratification in order to test this association. Methods·. Thirty families of inpatient adolescents from Jewish Ashkenazi origin, with a recent suicide attempt, were genotyped. All subjects were interviewed for clinical diagnosis, depressive and impulsive-aggressive traits and demographic data. Allele frequencies were assessed using the Haplotype Relative Risk method for trios. Results: No difference was found in allelic distribution between transmitted and non-transmitted alleles. There was no significant association of genotype with any of the clinical traits Conclusions: These preliminary results suggest that the 5-HT 2A T102C polymorphism is unlikely to be associated with suicidal behavior and related traits in adolescent suicide attempters.