Background: Standard physical education (PE) programs and the team-teaching methodology have rarely been evaluated to investigate their real efficacy in changing children's motor skills. Aims: The aims of this study are two-fold: The first aim is to evaluate the effectiveness of a PE program for improving coordinative motor skills in the team games of primary school-age children. The second aim is to investigate whether the program is or is not more effective when we employed team-teaching with two, instead of one, instructors. Participants and Setting: Participants were 205 normally developing children (48% male and 52% female) attending the third grade of a primary school in northwestern Italy. For the control group taught by their usual teacher, the mean age was 8.65 years (SD = 0.46); for the experimental group with one qualified PE instructor, the mean age was 8.63 years (SD = 0.48); and for the experimental group with two qualified instructors, the mean age was 8.95 years (SD = 0.52). Data Collection and Data Analysis: Baseline and post-test measurements were collected using the Coordinative Motor Skills Scale. The repeated measures analysis of variance was used for investigating the effects of the PE program on the children's motor skills. Findings: The findings showed that our PE program increased the children's coordinative motor skills in team games. Also, their coordinative motor skills increased more in the experimental conditions with two instructors than in the scenario with only one instructor. Conclusion: These results underline the importance of structured programs of PE implemented by experienced instructors in order to increase coordinative motor skills in team games during a sensitive growth period of childhood development.