Percutaneous epiphysiodesis using transphyseal screws (PETS) has been developed for the treatment of lower limb discrepancies with the aim of replacing traditional open procedures. The goal of this study was to evaluate its efficacy and safety at skeletal maturity. A total of 45 consecutive patients with a mean skeletal age of 12.7 years (8.5 to 15) were included and followed until maturity. The mean efficacy of the femoral epiphysiodesis was 35% (14% to 87%) at six months and 66% (21% to 100%) at maturity. The mean efficacy of the tibial epiphysiodesis was 46% (18% to 73%) at six months and 66% (25% to 100%) at maturity. In both groups of patients the under-correction was significantly reduced between six months post-operatively and skeletal maturity. The overall rate of revision was 18% (eight patients), and seven of these revisions (87.5%) involved the tibia. This series showed that use of the PETS technique in the femur was safe, but that its use in the tibia was associated with a significant rate of complications, including a valgus deformity in nine patients (20%), leading us to abandon it in the tibia. The arrest of growth was delayed and the final loss of growth at maturity was only 66% of that predicted pre-operatively. This should be taken into account in the pre-operative planning.