The Anterior Cruciate Ligament-Quality of Life (ACL-QOL) questionnaire is a patient-reported outcome measure used to assess the effect of an anterior cruciate ligament (ACL) injury on the lives of patients. It was originally written in English, which may affect its use when completed by nonnative English speakers. To translate and adapt the ACL-QOL to Spanish and provide evidence of its psychometric properties. Cohort study (diagnosis); Level of evidence, 2. A total of 183 patients with an ACL injury from 4 Catalan hospitals were included: 99 patients who had undergone ACL reconstruction (ACLR) completed the Spanish version of the ACL-QOL (ACL-QOL-Sp) twice (mean interval, 15.2 days) in 2 weeks for test-retest reliability, and 84 patients completed the ACL-QOL-Sp, the Lysholm knee scoring scale, the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale, and the 12-item Short Form Health Survey (SF-12) before and at 4 and 9 months after ACLR to assess responsiveness. The association between the ACL-QOL-Sp and the other outcome measures was evaluated with the Spearman correlation coefficient. The ACL-QOL-Sp showed good internal consistency (Cronbach alpha = 0.96) and test-retest reliability (intraclass correlation coefficient = 0.97). The standard error of measurement was 3.6, also suggesting the precision of measurements. The smallest detectable change was 9.98 in 94% of patients. No association was found between the ACL-QOL-Sp score and the Tegner score or SF-12 mental component summary score; however, a moderate correlation was found with the overall KOOS score (r = -0.545), Lysholm score (r = 0.509), and SF-12 physical component summary score (r = 0.607). The correlation ranged from weak for the KOOS-Symptoms subscore (r = -0.290) to moderate for the KOOS-Quality of Life subscore (r = -0.698). No ceiling or floor effects were observed. The ACL-QOL-Sp showed a moderate effect size (0.73) at 4 months but a large effect size (1.70) at 9 months. The ACL-QOL-Sp showed adequate internal consistency, test-retest reliability, and responsiveness in evaluating quality of life after ACLR in Spanish-speaking patients.