Abstract
An experiment is reported on the effects of a moral education programme based on cognitive‐developmental theory, at the high school level. Students were pre‐tested and post‐tested on Kohlberg's Moral Judgment Scale. Four different treatments were used with 96 suburban high school students attending four different high schools. The treatments extended over a period of nine weeks and involved 18 sessions with 50 minutes in each session. In an analysis of covariance on the post‐test scores, a significant difference was found between the groups.