Patient-reported outcome measures (PROMs) have been adopted as a way to measure patient self-rated physical function and health status for patients with anterior cruciate ligament (ACL) injuries. Although multiple PROMs exist and have been translated into various languages, the cross-cultural adaptation and validity of these PROMs for Spanish-speaking patients is unknown. To evaluate the adaptation quality and psychometric properties of Spanish-language adaptations of PROMs for patients with ACL injuries. Scoping review; Level of evidence, 3. Under PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we reviewed published studies related to adaptation quality and psychometric properties of Spanish PROMs in patients with ACL injuries. The methodological quality of the included studies was assessed using the Guidelines for the Process of Cross-Cultural Adaptation of Self-Reported Measures, the Quality Criteria for Psychometric Properties of Health Status Questionnaires, and the Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. The level of evidence for each PROM was determined based on the number of studies, methodological quality, consistency of results, and sample size. The initial search strategy identified 5687 articles. After removal of duplicates, 1882 titles were screened, and 114 articles were assessed for eligibility. Six articles were selected for final review, comprising 4 PROMs: the Lysholm knee score, the Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI), the Lower Extremity Functional Scale, and the Lower Limb Functional Index. Three studies followed all 6 processes for cross-cultural adaptation. None of the studies demonstrated all 14 domains required for cross-cultural validity (eg, description of translator expertise). The ACL-RSI achieved the highest level of evidence, with 3 of 9 domains demonstrating moderate evidence. This review identified 4 instruments that have been translated for Spanish-speaking patients with ACL injuries, none of which demonstrated appropriate adaptation or robust psychometric properties. The study highlights the need for improvement in PROMs for Spanish-speaking patients and the potential for mismeasurement and inappropriate application of PROM results in patients with ACL injuries.