Objective: The aims of this study were to examine health problems of children (4-12 years old at the time of the disaster) and adolescents (13-18 years old at the time of the disaster) before and after exposure to a fireworks disaster in the Netherlands (May 2000), to compare these health problems with a control group, and to identify risk factors for postdisaster psychological problems. Method: Because the electronic medical records of family practitioners were used, longitudinal monitoring of health problems from 1 year predisaster until 2 years postdisaster for both victims (N = 1,628) and controls (N = 2,856) was possible. Health problems were classified according to the International Classification of Primary Care. Results: Postdisaster increases were significantly larger in victims than in controls for psychological problems, musculoskeletal problems, stress reactions, and symptoms of the extremities. Children 4-12 years old presented larger increases in sleep problems compared with controls, whereas children 13-18 years old showed larger increases in anxiety problems than their controls. Significant predictors for postdisaster psychological problems included being relocated, presenting predisaster psychological problems, and a low to medium socioeconomic status. Conclusions: Children and adolescents exposed to a disaster are at risk of long-lasting increases in both psychological and physical health problems. Postdisaster interventions should focus on those who were relocated and presented predisaster psychological problems. (Contains 3 tables.)