Introduction. Cyclops syndrome is one of the causes of failure of anterior cruciate ligament reconstruction. The aim of the study was to examine the quality of life of patients who had this complication and its consequences till the return to unrestricted (sports) activities. Material and Methods. During an eighteen-year follow-up of 4330 patients, cyclops syndrome was found in 71 patients (1.64%). This study included 60 of them, who agreed to fill out a questionnaire and functional scoring scales. Results and Discussion. The mean Tegner score was 5.95 and Lysholm score was 86.13 points. After the arthroscopic removal of cyclops lesion, excellent results were found in 22 patients (36.7%), good in 19 (31.7%), poor in 16 (26.7%) and very poor in three cases (5%). On average, athletes lose 10 months from injury to anterior cruciate ligament reconstruction. It takes at least 6 months to return to competitive sports. If cyclops lesion occurs, it takes approximately 10 months to arthroscopy, and on average 3 months of postoperative recovery. Conclusion. Cyclops lesion is a complication that significantly compromises the outcome of anterior cruciate ligament reconstruction, in terms of functional scores, subjective symptoms, the intensity of sports activities, and quality of life. Arthroscopic removal of the cyclops lesion leads to satisfactory postoperative results, but athletes lose 2.5 years on the whole, from injury to return to unrestricted sports activities.