Psychopathy is a multidimensional construct characterized by an interpersonally manipulative and emotionally detached personality profile that differentiates it from other antisocial syndromes. Previous research with youth has linked the long allele of the serotonin transporter gene in the presence of environmental stress with the interpersonal and affective traits of psychopathy, but these relationships have yet to be examined in relation to adult psychopathy. Consequently, we examined how serotonin transporter (5-HTTLPR) polymorphisms, monoamine oxidase-A (MAO-A) variants, and childhood abuse measured with the Childhood Trauma Questionnaire relate to dimensions of psychopathy in a forensic sample of 237 men with elevated levels of environmental adversity. We found that the emotional deficits characterizing the affective factor of psychopathy, as measured by the Psychopathy Checklist: Screening Version, were highest among carriers of the 5-HTT long allele. Furthermore, the impulsive and irresponsible lifestyle features of psychopathy were higher among low-activity than high-activity MAO-A carriers. These genetic effects were unexpectedly not moderated by a history of childhood abuse. Results provide evidence on the molecular genetics correlates of psychopathic traits in adulthood, relationships that should be investigated further in future research.