Background Dislocations of the sternoclavicular joint are rare injuries caused by massive forces applied to the joint. A high rate of complications has been reported following this injury emphasizing the importance of an accurate diagnosis and therapy. Methods We report a series of patients with chronic anterior or posterior sternoclavicular instability treated with figure-of-eight gracilis- or semitendinosus-tendon reconstruction. Tendon grafts were collected from the patient's ipsilateral knee. Preoperative and postoperative DASH scores were compared to evaluate the outcome. Results Six patients (mean age, 22 years; range 15-46; male = 3; female = 3) were included. The patients sustained an isolated dislocation of the sternoclavicular joint resulting from a high-energy trauma. Anterior instability was observed in 3 patients, posterior instability in 2 patients and the remaining patient showed multidirectional instability. The mean time from injury to operation was 8 months (range, 4-33). The semitendinosus tendon was used in 4 patients, the gracilis tendon in 2 patients, respectively. Follow-up examination was after 22 months (range, 14-34). The DASH score improved from 54.3 points (range, 45.7-68.8) preoperatively to 28.8 points (range, 25.8-34.5) postoperatively. All patients returned to full activity without limitations including competitive contact sports. Conclusion Stabilization of the sternoclavicular joint with the figure-of-eight technique seems to be a feasible alternative for young and active patients with remaining instability following conservative treatment.