The aim of this study was to establish possible genotype-environment interaction in high-risk and low-risk adoptees' vulnerability to schizophrenia. The study population consisted of a subgroup of 41 adoptive families with a high genetic risk adoptee and 58 families with a low genetic risk adoptee from the Finnish Adoptive Family Study of Schizophrenia. Communication style was assessed based on the Communication Deviance (CD) of the adoptive parents, and the adoptees' vulnerability indicators were measured with the Minnesota Multiphasic Personality Inventory (MMPI). Taken separately, only the genetic liability to schizophrenia, but not the communication style of the adoptive parents, was significantly associated with the Lie, Correction and Hostility scales in the MMPI of the adoptees. Analyses of the genotype-environment interactions showed that the high-risk adoptees with high-CD rearing parents had an increased risk of vulnerability on the MMPI Social Maladjustment scale compared with the corresponding low-risk adoptees. Genetic vulnerability to schizophrenia and genotype-environment interaction are manifested in adoptees' MMPI.