Sternal nonunion as the result of cardiac intervention or trauma remains a morbid condition with serious sequelae. Patients often report pain with breathing, coughing, and/or movement. The authors present 6 patients that were diagnosed with sterile sternal nonunion after cardiac procedure (4) or trauma (2). The cardiac patients presented 5, 7, 15, and 60 months after their cardiac procedure; the trauma patients presented 8 and 12 months after the accident. Diagnosis was made based on the clinical triad of sternal instability, pain, and absence of infection. Management with open reduction and internal rigid plate fixation with Sternalock plates (W. Lorenz Surgical, Inc., Jacksonville, FL) was performed on all 6 patients. There was no incidence of subsequent infection. Pain completely resolved in all patients. All wounds healed to completion, and bone healing was assessed clinically with the absence of instability and pain and follow-up chest radiographs.