Introduction Foster care institutions provide basic needs for children deprived of familial life because of death, divorce, or imprisonment of either one or both parents, or because of severe poverty in a family; some children are picked off the streets. This occasionally leads to different behavioral disorders, the most common of which are attention deficit hyperactive disorder and conduct disorder, or psychiatric disorders such as major depressive disorders and anxiety, or psychological disturbances such as aggression. Aim The current work is a cross-sectional study of the behavioral, emotional, and psychiatric disorders prevalent among children in two foster homes in Banha city, Qalyubia governorate. The study aimed to highlight the difference between psychological and psychiatric disorders among boys and girls living in foster homes, with special interest on levels of aggression in such institutions. Participants and methods Forty boys and 20 girls of ages 5–15 years were included in the study. A thorough medical, developmental, psychological, and psychiatric examination was conducted. All were tested for aggressive behavior with the Hostility Questionnaire for Children. Results There was a high level of aggression (verbal 85%, physical 80%, and emotional 91.7%) and a high level of disruptive behavior and learning difficulties (80%); physical and verbal abuse was seen in the entire studied sample; 46.7% had been sexually abused; 58% showed self-injurious behavior; 23.3% displayed truancy; 15% were drug abusers; 8.3% were smokers; 31.7% suffered from enuresis; and 13.3% suffered from encopresis. Conclusion Children living in foster homes need attention because of the difficult conditions they live under. Psychiatric assessment should be performed routinely.