The Montessori method is an attractive alternative to traditional education for many parents in the United States of America and abroad (Lillard & Else-Quest, 2006). There are between 4,000 and 5,000 private Montessori programs in the United States, and thousands more internationally (American Montessori Society, 2016; Lillard & Else-Quest, 2006, North American Montessori Teachers' Association, 2016; USA Montessori Census, 2016). Apart from private Montessori schools, there are at least 500 public Montessori schools throughout the United States (National Center for Montessori in the Public Sector, 2016). Numerous qualitative narratives espousing the benefits of Montessori education to enhance executive functioning (e.g., working memory, self-regulation, and reasoning abilities), academic achievement, and social competence are readily available. Despite the existence of these narratives, hardly any empirical consensus regarding the actual utility of the Montessori approach can be found (Diamond, 2010). The primary objective of this review will be to examine the effectiveness of Montessori education in improving academic and behavioral outcomes compared to traditional public school education. The secondary outcomes will be to determine what factors moderate the reported effectiveness of Montessori education. Possible moderators include the age of students, setting, type of teacher training, student characteristics, study quality, study design, among others.