Pelvic and acetabular non-unions are rare but considerably demanding complications. Pelvic non-unions are frequently combined with malunions. As the treatment will be extremely challenging after the occurrence of a pelvic non-union, all efforts should be given not to pass the first three weeks after the injury, which is the effective period of the surgical treatment. Symptomatic pelvic non-unions should be treated surgically. The surgical treatment comprise debridement, approximating the fracture ends, filling the gaps with bone grafts, and stable internal fixation. A staged procedure should be followed in complex vertical instable pelvic non-unions and malunions. In the first stage an extensile posterior released should be done in prone position; followed by the exposure, release, correction and reduction of both anterior and posterior structures in supine position. In the end, the patient is turned again to the prone position, allowing reduction of the posterior pelvic ring and then a posterior stabilization is added.