Achenbach's Child Behavior Checklist (CBCL) and Teacher's Report Form (TRF) were administered to school children aged between 7-11 comprising a non-referred sample (n = 349) drawn from the whole country. Those were the first data on the CBCL and TRF in Croatia. Both in the CBCL and TRF boys had higher scores compared to girls in the Externalizing and Total Problems scale (p < 0.01 and p < 0.05). Parents rated higher scores to the Internalizing and Externalizing scales and the Total Problems scale in both sexes (p < 0.01 and p < 0.05), with the exception of the Internalizing scale in boys. Parents are very important observers of mental health problems in children.