The body of research shows that teachers’ educational style and type of thinking can have fundamental effects on children. This study set out to evaluate the effectiveness of the Child Development Educational Program on improving teachers' educational styles. The present quasi-experimental study had a pre-test, post-test design without a control group. The sample included the teachers of 7-11 year-old students in a private school in Tehran who were selected through convenience sampling method. The Teacher Educational Style Questionnaire was used as the pretest and the sample participated in 5 two-hour weekly sessions. After the workshop, the post-test was administered and the research data were analyzed via dependent t-test. Results revealed that the child development workshop could significantly increase the problem-solving method in teachers and decrease their scores on the three other methods, namely punishment and reprimand, advice without explanation, and advice with explanation (p<0.001). In general, the findings showed that the Child Development Educational Program played a significant role in improving the educational style of teachers. When teachers participate in such educational programs, they learn alternative solutions to punishment or advice and encourage their students to solve various problems.