Objective: To assess the anatomical and functional results after surgical management of leg shaft mal-union in African environment. Methodology: This was a retrospective study of patients operated for leg mal-union at Brazzaville University Hospital between January 2014 and December 2018. The studied parameters were epidemiological and therapeutic. The anatomical evaluation was based on the quality of the leg's relaxation and bone healing, which was indicated on standard X-rays. The functional evaluation was based on Thorensen's criteria. Results: Five patients were selected for this study. There were 3 men and 2 women with an average age of 39 years with extremes of 27 and 59 years. Three patients were treated with locked intramedullary nail and 2 patients with screwed plate. At an average follow-up of 9 months, bone consolidation was achieved in all our patients. The average consolidation time was 4 months (range 3 to 7 months). We noted 1 case of residual mal-union in valgus (5˚) on screwed plate and 1 case of valgus angulation (5˚) on locked intramedullary nail. Walking was considered normal in 3 patients. The wearing of a 2 cm heel was indicated in 2 patients. According to Thorensen's criteria, the overall results were considered good in 3 patients and average in 2 patients. Conclusion: Leg shaft mal-union are likely to cause serious functional issues. Their treatment is strictly surgical and osteotomy is the only management option to restore the anatomy of the deformed limb.