Background: Genu valgum deformity is exaggerated valgus alignment of lower extremity mechanical axis in knee with a joint line that slopes superolaterally and is corrected by distal femoral osteotomy. In this study the results of treatment and satisfaction in patients with genu valgum were evaluated according to knee society score (KSS) and changes in pre-operation and post-operation lower extremity mechanical axis were compared to each other. Methods: The present study is a cross-sectional study that was performed on 27 patients (30 knees) who have had distal femoral varus osteotomies between 2005 to 2011. Patient’s data were collected from hospital documents, pre-operation and post-operation alignment views and physical exams of operated patients. Radiographs were from the lower extremities and including three joints of hip, knee and ankle (alignment view). Mechanical axis of femur and tibia were drown and they were compared to each other. For measuring patient satisfaction, KSS score was used. All data was collected and evaluated by SPSS 16 software. Results: In this study, 30 knees (in 27 patients) by mean of 30.7±3.36 months follow- up, (range, 5-76 months) were evaluated. The mean of ages in patients was 19.66±4.35, (range 10-34 years). Ten cases (37%) of valgus were on the right side and 14 cases (52%) on the left side and three (11%) cases were reported on both sides. Based on Student’s t-test, there was a significant difference in post- operation lower extremity mechanical axis. The mean of KSS score was 82.52 and the score was defined as 60.7% excellent, 25.1% good, 7.1% fair, and 7.1% poor in patients. According to the results of study, in five patients were non-union and re-operated. Conclusion: Distal femoral varus osteotomy is a reliable procedure in knees with valgus correction. This procedure with precise selection of patients, have acceptable end results.