The focus on gender-specific genes associated with female suicide is justified by the possible dimorphic nature of the serotonergic system and by the greater number of suicide attempts in females. Gender specificity in epidemiology and psychopathology of suicidal behavior suggests an X-linked genetic factor. In the present study we performed analysis of some serotonergic system genes located on the X chromosome, namely the HTR2C, MAOA and MAOB, in suicide attempters, separately in men and women. Cases for this study were 283 suicide attempters: 94 men and 189 women. The control group consisted of 261 healthy volunteers: 133 men and 128 women. Three polymorphisms: the HTR2C Cys23Ser, A/G in intron 13 o f the MAOB and EcoRV-RFLP of the MAOA were analyzed using PCR technique. We computed multivariative logistic regressions to examine the joint effects of several variables in predicting the suicidal group. Sex was a significant predictor of suicide group (p<0.001). MAOB*A allele (coding high activity enzyme) was associated with suicide both in men (p=0.024, OR=2.13) and in women (p=0.016, OR=1.59). Allele frequencies of the MAOA and HTR2C did not differ significantly between the control and suicide groups, neither in men, nor in women. MAOB (p=0.003) and MAOA (p=0.02) significantly predicted the suicide group independent of the effect of sex. Our findings indicate the contribution of the MAO genes to susceptibility for suicidal behavior. This work was supported by INTAS Postdoctoral Fellowship Ref. Nr 04-83-3802, Grant of President of Russian Federation Nr.-1866.2005.4 and grant of RSCI 06-06-00163?.