Interpersonal victimization is a pervasive hardship for children and adults. Previous research has attempted to identify individual characteristics and environmental conditions that might predispose individuals to these experiences. Nonetheless, no research project has been designed to clarify the extent to which genetic and environmental factors contribute to the risk of, and to the associations between, multiple forms of victimization during childhood and adulthood. Moreover, victims of childhood abuse and neglect are more likely than non-victims to develop psychopathology. However, whether different types of childhood victimization confer risk for different mental health problems or, rather, for psychiatric comorbidity, has rarely been addressed in genetically controlled studies testing multiple associations simultaneously. Hence, we investigated the genetic and environmental etiology of interpersonal victimization and psychiatric comorbidity in a nationally representative sample of Finnish adults. In Study I, we estimated genetic and environmental influences on the risk of childhood victimization. We found that genes and environments shared by siblings increased the risk for multiple victimization, especially by related individuals, while unshared environmental exposures increased the risk of specific adversities, particularly sexual abuse. We also found sex differences in the prevalence and etiology of childhood victimization, in particular emotional and sexual abuse. In Study II, we examined genetic and environmental influences on the risk of adult sexual victimization as well as its phenotypic and genetic associations with childhood victimization. We observed that environmental exposures, especially outside the family, largely explained the risk of adult sexual victimization. Childhood emotional abuse was the strongest predictor of adult sexual victimization. Notably, the same etiological factors influenced multiple childhood victimization and adult sexual victimization. In Study III, we explored the patterns of psychiatric comorbidity of core internalizing, externalizing, and less investigated problems like sexual distress. Alongside the previously known dimensions of psychopathology, we identified a novel dimension accounting for the covariance of body-related problems. Body-related problems were strongly associated with core internalizing problems and affected women and middle-aged participants more than men and young adults, respectively. In Study IV, we investigated the impact of gene variants and early adversities on the comorbidity and distinctiveness of body-related and core internalizing mental health problems. We identified one etiological pathway for core internalizing and one for body-related and associated symptoms. Childhood victimization contributed to internalizing more than body-related problems, and emotional maltreatment was the strongest predictor of these outcomes. However, observed associations were small and explained by shared genetic effects for core internalizing, and by shared genetic and environmental effects for body-related problems. Our findings suggest that gene variants may influence the risk of interpersonal victimization, especially during childhood. This means that some individuals are at higher risk than others, due to a correlation between their genetic make-up and the environments that they inherit, evoke, and seek out. As a result, preventive practices should account for individual risk profiles to effectively protect particularly vulnerable individuals. Emotional abuse and neglect were especially harmful in terms of later risk of adult sexual victimization and mental health problems. This might be because these forms of maltreatment are usually perpetrated by parents, are difficult to detect and, therefore, more often continuous stressors than isolated experiences. Our findings also help to explain why women experience elevated risk of victimization compared to men: Girls might be at increased risk of emotional and sexual abuse due to sex-specific genetic influences on traits exploited by perpetrators, and women might be at increased risk of sexual victimization because many environments are unsafe for them. Lastly, our work supports the notion that the longitudinal associations observed between childhood victimization and adult sexual victimization and mental health problems might be accounted for by the same etiological factors.