The aim of this study was to explore child and adolescent personality in the Russian culture, addressing gender and age differences, and to examine personality and family effects on children's Internalizing and Externalizing problems. Parents of 1,640 Russian children aged 3-18 years completed the Inventory of Child Individual Differences measuring personality, the Strengths and Difficulties Questionnaire measuring problem behavior, and reported about family background. Girls scored higher than boys on the Conscientiousness domain and on the Intelligent and Considerate scales, but lower on Activity. In younger children, Extraversion was higher; in older children, Agreeableness, Conscientiousness and Shyness were higher; Distractibility was highest in early adolescence. The gender and age differences were small. Personality explained about 30% of variance in children's Internalizing problems, and 50% in Externalizing problems; family factors contributed less than 4%. Internalizing Problems were linked to higher Neuroticism and lower Extraversion; Externalizing Problems were linked to higher Extraversion, lower Conscientiousness and Agreeableness. For both types of problems, harsh parenting was a risk factor, while SES and family cohesion were associated with lower problem levels. Models linking personality with children's problem behavior were similar in preschool, middle childhood, early and late adolescence. (Contains 5 tables and 3 figures.)