OBJECTIVE To compare the effects of Montessori education and traditional education on the intellectual development in children aged 2 to 4 years. METHODS Children aged between 2 to 3 years who were enrolled in a kindergarten in September 2006 were randomly assigned to the Montessori education and the traditional education groups. In addition to receiving the traditional education, the Montessori education group participated in the two-hour Montessori pedagogical activities every day. The intellectual development was evaluated by the Neuropsychological Development Examination Format for Children Aged 0~6 years published by Capital Pediatrics Research Institute at enrollment and one year after the trial. RESULTS There were no significant differences in the intelligence growth level between the Montessori education and the traditional education groups at enrollment. After one year, the levels of fine movements, adaptation ability, language, and social behavior developments in the Montessori education group were significantly higher than those in the traditional education group (p<0.05 or 0.01). The intelligence increasing scores of the large motor ability, fine movements, language, social behavior and development quotient in the Montessori education group were also higher than those in the traditional education group (p<0.05 or 0.01). CONCLUSIONS Montessori education can promote the development of large motor ability, fine movements, language, and social behavior in children.