Objective: To detail the principles of calcaneal lengthening according to the EVANS technique and to evaluate the clinical and radiological results.Methods: Monocentric retrospective descriptive cross-sectional study. Patients operated in the orthopedic department at the children's hospital Béchir HAMZA of Tunis, during the period from January 2016 to December 2018 with a minimum of one year of follow-up. This study involved 12 children and 15 feet. The evaluation of the results was clinical and radiological.Results: Mean age was 12 years. The sex ratio was 1.4. Surgery was performed on the right side in 4 cases, on the left side in 5 cases and bilaterally in 3 cases. The average preoperative AOFAS score was 61, postoperative 90. The overall result was excellent in 11 cases (11 feet) and good in 4 cases. The postoperative radiological result was close to normal values. Bone consolidation was noted in all patients.Conclusions: Calcaneal lengthening using the EVANS technique has proven to be effective for idiopathic flatfoot and the peroneal graft can replace the tri-cortical iliac graft, with less morbidity.