Objective To investigate a surgical method to reconstruct the posterior lateral knee complex using autologous semitendinosus and thin femoral tendons and to observe its clinical efficacy. Methods A retrospective study of 15 patients, 10 males and 5 females, with an average age of 28.2 years (18-45 years), who were reconstructed with this surgical method from May 2005 to May 2009. All patients were followed up with postoperative assessment of bilateral knee mobility, preoperative and postoperative 30° position dial test and 30° position inversion test, and preoperative and postoperative Lysholm score of the affected knee. Results All 15 patients in this group received postoperative follow-up with a mean follow-up time of 37.4 months. The preoperative 30° dial test was 2+ in 4 patients, this test was 3+ in 11 patients, and the postoperative 30° dial test was 1+ in 3 patients, while 12 patients were negative. The preoperative 30° position inversion test was 2 degrees in 3 patients and 3 degrees in 12 patients. Postoperatively, the 30° position inversion test was 1 degree in 3 patients and 0 degree in 12 patients. The stability of internal and external rotation of the affected knee improved significantly after surgery (P<0.05). The preoperative Lysholm score was (57.27±11.47) and the postoperative score was (91.27±5.85), and the difference between the two was statistically significant (t=12.380, P=0.000). All patients resumed daily work with improved knee function and significantly increased stability. Conclusion The application of autologous semitendinosus and thin femoral tendon to reconstruct the posterior lateral knee joint complex is a simple operation with good postoperative knee function and satisfactory clinical efficacy.