This study investigated the effectiveness of parental skills training using a cognitive-behavioral method in order to reduce the behavioral problems of the preschool children. This was a quasi-experimental study with a pretest-posttest design. The statistical population of the study consisted of all parents of the preschool children in Isfahan in educational year of 2014-2015. To this end, 32 parents (64 persons) who obtained 1.5 SD higher than the reported mean in response to the behavioral problems of their children, were randomly selected and divided into two groups of 16 parents (32 persons) as the treatment and control groups based on the random distribution. After conducting the pre-test for both groups, the treatment group received parental skills training using a cognitive behavioral method for six sessions during one month; however, the control group received no training. Then, for both groups, post-test was implemented and follow-up study was conducted. In order to assess the behavioral problems of the children, Child Behavior Checklist (CBCL) was used. Finally, the data were analyzed using the analysis of covariance. The results showed that the mean of the treatment group was significantly reduced compared to that of the control group in terms of the behavioral problems, anxiety, depression, somatization, social problems, thought problems, attention problems, rule-breaking behaviors, aggressive behaviors, and other problems. It could be concluded that cognitive behavioral parenting skills training was an effective way to reduce the children’s behavioral problems.