A quasi-experiment was undertaken to test the effect of Montessori practical life activities on kindergarten children's fine motor development and hand dominance over an 8-month period. Participants were 50 children age 5 in 4 Montessori schools and 50 students age 5 in a kindergarten program in a high-performing suburban elementary school. Children were pre- and posttested on the Flag Posting Test, an individually administered test of fine motor skill requiring children to place tiny flags mounted on pins into preset pinholes. Students in the Montessori treatment group demonstrated significantly higher accuracy, speed, and consistent use of the dominant hand on the posttest, adjusted for pretest differences and gender. Effect sizes were moderate for accuracy and speed (ds=.53 and .37, respectively) and large for established hand dominance ([delta R squared] =.35). Longitudinal research on the effects of early childhood programs emphasizing the reciprocal interplay of cognitive and physical aspects of activity is recommended. Practice or Policy: The findings argue for a balanced approach to early childhood education that maintains the importance of physical activity and fine motor development in conjunction with cognitive skills. Montessori practical life activities involving eye-hand coordination and fine motor skills can be integrated into programs. (author abstract)