The purpose of the present study was to investigate the effect of an exercise program emphasizing coordination on the motor proficiency of preschool aged children. One hundred and thirteen children, aged 4-6 years (M= 60.17 months, SD=6.43 months) living in Southern Greece, enrolled in the study. The 57 children of the experimental group (EG) attended the intervention program for 28 weeks, while the 56 children of the control group (CG) did not participate in any organized physical activity program. Both groups were tested with the “Democritus” Psychomotor Assessment Tool for Preschool Children (PAT-PRE) (Kambas, Aggeloussis & Gavriilidou, 2003) five times (one before program’s start, one after its end and three in the meantime). The ANOVA with repeated measures that was applied showed that, while both groups (EG and CG) displayed an improvement in their performance, the EG surpassed statistically significantly the CG at the fourth measurement and maintained that difference at the fifth one. It seems that an exercise program emphasizing coordination can notably improve children’s motor proficiency.