The Non-union is a frequent complication of the femoral neck fracture. Its genesis implicates several factors in particular the age, the characteristics of the fracture, the state of the femoral head and the type of the treatment (absence ortherapeutic imperfection). Several techniques of femoral valgus osteotomy were described for the treatment of these non-union, our technique using the ?dynamic hip screw? is an original therapeutic method which gives good performances. Our study concerns 09 cases of femoral neck non-union treated by valgus osteotomy at the university hospitalMohammed VI of Marrakech from January 2013 to August 2016.The averageage of our patients was 46 years. The valgus angle of the osteotomy was between 25? and 40?with an average of 29?. All our patients were healed with satisfying functional results. Indeed the type of fracture and his initial treatment also the type and the characteristic of the non-union doesn?t influence the consolidation. Femoral head necrosis is a frightening complication which evolves on its own account and may occur at anytime. It is a significant factor for functional degradation and no cases have been noticed in our series. The quality of the results which we got, encourages us to suggest this treatment in all femoral neck non-union cases among the young patients, if the head is supposed alive.