Although most Jewish supplementary religious school principals have graduated from various academic training programs, there are no data about how these programs sufficiently prepare educational leaders. This study examined the essential leadership and management skills of effective Jewish religious school leaders, and assessed their preparation to undertake the key challenges of this complex job. This study also investigated the principals' perceptions about their training and whether they experienced a knowledge gap as school leaders. The respondents felt unprepared to conduct essential tasks--such as working with lay leaders, managing human resources, and planning budgets--after completing their training programs.