Restoration of fracture alignment by osteotomy is crucial for the management of humeral nonunion. In the present study, we introduced a new way of osteotomy (Z-shaped) in treating humeral shaft nonunion secondary to failed plate osteosynthesis. Clinical data of 24 patients with humeral shaft nonunion following implant failure (from 2010 to 2014) were retrospectively evaluated. These patients underwent Z-shaped osteotomy in revision surgery after the initial surgery, plate osteosynthesis, was failed. Outcomes were evaluated using visual analogue scale (VAS) and Constant and Murley score. Repeated analysis of variance (ANOVA) was used for statistical analysis. Patients were followed up for a minimum of 24 months (26.83±4.33 months). The operative time was 102.33±10.16 min, and hospital stay averaged 9.75±2.13 days. All patients achieved clinical union at the latest follow-up. Complications included radial palsy (n=1) and superficial wound infection (n=1). The postoperative VAS scores decreased significantly compared to preoperative score (F=257.99, P<0.01). Constant and Murley score increased and reached 81.33±0.95 at 24 months' follow-up (F=247.35, P<0.01). Among all the cases, 15 cases were graded as "excellent", and 9 as "good". In conclusion, Z-shaped osteotomy was easy to perform, and it provided additional medial support with more bone contact areas. Revision surgery using locking plate and Z-shaped osteotomy achieved high union rate and improved functional outcome. It was a reasonable and safe option for treating humeral nonunion following implant failure.