This research is conducted to examine the predictor effects the behavior problem level has on the school adjustment variable. With this objective, the sample research group consists of 136 children (having normal growth) between 5-6 years old attending preschools affiliated with the Ministry of National Education, and located in the city centre of Corum province. In this research the Teacher Rating Scale of School Adjustment and the Preschool Behavior Questionnaire were applied to the teachers. Data analysis that was used to provide descriptive statistics includes Pearson product-moment correlation coefficients and simple linear regression analysis. The data gathered from the study was analyzed using the SPSS 18.00 program package. Study results have concluded that there is a negative significant relationship between the level of behavior problems sub-scale dimension (hostile-aggressive behavior, anxious-weepy, and hyperactivity-distractibility) and school adjustment. According to the results of the research, behavior problems among 5-6 year old children have predictor effects on the variables related to school adjustment.