We retrospectively examined Cozen's fractures in children treated with a cast in extension with a varus mold applied as described by Rang. To our knowledge, no study has examined the effectiveness of this treatment. Our review included 14 patients with an average age of 3 years. The average time to valgus deformity was 8.8 months (range 5-15 months). Follow-up was 16.2 months (range 6.7-42.8 months). Seven (50%) patients developed a 5° valgus deformity in addition to the normal valgus of the contralateral side. In conclusion, treatment with a long leg cast with the knee in extension and a varus mold minimized the valgus deformity compared with previous reports in the literature.