The purpose of this study was to assess percutaneous femoral distal hemi-epiphysiodesis using transphyseal cannulated screws in order to correct valgus angular deformities of the knee in pediatric and adolescent patients.This is a prospective longitudinal study in which our experience with 52 patients is described.We evaluated 100 knees surgically managed for pathologic genu valgum over a 68-month period. The average age at surgery for boys and girls was 14 years and 7 months (range 12.7-15.1 years) and 13 years and 6 months (range 12.9-14.8 years), respectively. The pre-surgical tibiofemoral (T-F) angle was measured at between 14.17° and 35.3°, and the postoperative T-F was measured at between 6.2° and 15.8° (7.2° ± 0.65°, mean ± standard deviation), for an average correction of 0.73° ± 0.45° per month). The mean follow-up after surgery was 3.2 years (range 2.3-5.3 years).We demonstrate a simple, fast and reproducible surgical technique for percutaneous epiphysiodesis with low morbidity, rapid rehabilitation and a rapid return to school and sports activities. We experienced no complications, such as overcorrection, undercorrection, postoperative hematoma or infection. We conclude that percutaneous screw epiphysiodesis is an excellent option for the treatment of genu valgum in adolescents.