To assess the effectiveness of the life skills course in improving students' self-efficacy and assertiveness two student samples were drawn from among all first year high school students in Tehran, one from schools offering the course and the other from those not doing so, totaling to 615 students. The necessary data were collected using three questionnaires. Data analyses revealed no effect on self-efficacy and assertiveness, perhaps because all schools offering the course lack at least one factor dealing with professional competencies of teachers or curriculum implementation.