Introduction <p>This study aimed to compare the prevalence of cyclops lesions and the clinical outcomes between two types of anterior cruciate ligament (ACL) reconstruction using a truncated remnant technique: tie with allograft ACL reconstruction and re-tensioning of remnant ACL with allograft ACL reconstruction.</p> Materials and Methods <p>This is a retrospective study of 58 cases of ACL reconstruction using a truncated remnant preservation technique performed by a single surgeon from March 2019 to December 2022. Second-look arthroscopy was performed in each group, and pathologic evaluation was performed focusing on cyclops lesions. The cases were divided into two groups according to the type of remnant technique: tie with allograft ACL reconstruction group (<i>n</i> = 16) and re-tensioning of remnant ACL with allograft ACL reconstruction group (<i>n</i> = 42). We evaluated the prevalence of cyclops lesions and the clinical outcomes in the two groups using follow-up magnetic resonance imaging and second-look arthroscopy.</p> Results <p>No difference in patient characteristics was observed between the two groups. The clinical outcomes showed no significant differences between the two groups.</p> Conclusion <p>Re-tensioning of remnant ACL with allograft significantly reduces cyclops lesion occurrence compared to the tie technique, while maintaining comparable clinical outcomes. This technique is particularly beneficial in cases with sufficient remnant tissue and minimizes complications associated with cyclops lesions, such as extension loss and the need for secondary surgical interventions. Therefore, we recommend re-tensioning of remnant ACL with allograft ACL reconstruction.</p> Clinical Trial Number <p>Not applicable.</p>