The purpose of this study was to test the applicability of a standardized procedure for assessing Icelandic children's behavior/emotional problems and competencies, and to identify differences related to demographic variables. This study focuses upon the method of using the Child Behavior Checklist by Achenbach to estimate the self-reported prevalence by parents and adolescents of emotional and behavior problems in children from 2-16 years of age and self-reported prevalence of adolescents from 11-18 years, selected at random from the general population, both in urban and rural areas. The information was obtained by mailing lists with a letter to parents of children 2-10 years of age. The lists for adolescents 11-18 years of age were distributed by teachers in school. Those adolescents who were not in school received the lists by mail at their homes. The Child Behavior Checklists used for analyses were completed by 109 parents of 2-3 year old children; 943 parents of 4-16 year old children, and 546 non-referred adolescents from the general population. The rate of response was lowest for the youngest age group (47%), but increasing to 62% with increasing age of the child. The response rate among the adolescents answering the Youth Self Report was 64%. Comparisons are presented with the Child Behavior Checklist for this study with Dutch, American, French, Canadian, German and Chilean samples and show striking similarities in four of these countries in behavior/emotional problems reported. The present study prevalence data behavior/emotional problems in Icelandic children from the general population from 4-16 year olds for 943 children is 17.5 (boys 19.1; girls 15.).