The present study was conducted to determine the effect of education based on the existentialist approach on the development of moral judgment and academic achievement of fourth grade elementary school students. This study was a quasi-experimental study with a pre-test-post-test design with a control group. Using questionnaires, Sinha and Varma's Moral Judgment Test (1998), Pham and Taylor's Academic Achievement (1990), and educational protocols designed based on the William Perkey model, 60 fourth grade elementary school students in Jerusalem were selected through convenient sampling in 1402-1403 and placed in two experimental groups of 30 and control groups of 30. The experimental group received 20 sessions of the existentialist education program, and the control group did not receive any training in this area. After the intervention, the development of moral judgment and academic achievement of students in both groups were measured again. Multivariate analysis of covariance (MANCOVA) was used to analyze the data. This research, in agreement with the results of similar studies, expresses the fact that education based on an existentialist approach has an effective role in the development of moral judgment and academic achievement of students.