The present study aimed to assess the main effects ofAVPRIA (rs11174811, RSI) and AVPRIB (rs28632197, rs33911258) gene polymorphisms, as well as haplotypic, GxE and GxG effects on personality trait variation in 1018 healthy individuals, considering gender and ethnicity confounding. Haplotype analysis revealed an association ofAVPRIA C*S- and C*L-haplotype (rs11174811 and RS1, respectively) and increased (PFDR= 0.016) or decreased (PFDR = 0.031) Extraversion (EPI) in Bashkirs, respectively. The association of AVPR1B G*A-haplotype (rs28632197 and rs33911258, respectively) and decreased Self-transcendence (TCI-125) (P(FDR) = 0.040) was demonstrated in the total sample and in Udmurts. GxE analysis revealed that the birth season modulated the involvement of the AVPR1A (rs11174811) gene marker in the variation of Persistence (TCI-125) in the total sample (P(FDR) = 0.012). The modulating effect of several environmental factors (ethnicity and birth season) on the association of AVPR1A and AVPR1B gene polymorphisms and personality traits was established.