The present study provides prevalence data on behavioral and emotional problems in Dutch preschool children from the general population. The Child Behavior Checklist for ages 2-3 (3) was completed by parents of 421 children aged 2-3 living in the Dutch province of Zuid-Holland. Mean 3-week test-retest reliability of the instrument was .79 (pearson correlation) and the mean interparent agreement was .47. The CBCL/2-3 scores correlated positively and significantly (mean r of .65) with the BCL, an instrument designed to measure behavior problems, and not substantially (mean r of -.06) with the MCDI, an instrument to assess the child's level of general development. For each of the 99 problem items the prevalence rates were presented graphically for boys and girls in 6-months age-groups. The prevalence rates of individual problem items ranged from 1% to 80%. Sixteen percent of the items was scored for more than half of the sample, indicating that the behavior covered in these items may be quite common in young preschool children. In this sample 7.8% of the children were estimated to have a behavior problem, which compares well to the rates found in other studies. No age, sex, or SES differences in total problem scores were found. Almost all significant age, sex, and SES differences found for individual items were small. Age differences found for individual problem items probably reflect the growing self-other differentiation in 2-3-year-olds. Analysis of sex differences revealed that boys were rated to be more aggressive and oppositional and as having more developmental problems, and that girls were rated to have more sleep problems. SES differences were found for items which reflect hyperactive, undercontrolled, dependent, and depressed behaviors. Comparison of problem scores for referred and nonreferred preschool children indicated higher scores for referred children on 72 of the 99 problem items. The largest differences were found for the items Doesn't get along with other children, Wants a lot of attention, and Can't concentrate. Based on the total problem score 70 percent of the children could be correctly classified as referred or non-referred. A large percentage of children, however, was incorrectly classified based on the total problem score alone.