This study examined the relationship between participation restrictions in activities of daily living and sports following anterior cruciate ligament reconstruction (ACLR) and the status of knee structures, performance-based activity limitations, and impairments. Fifty subjects (36 men, 14 women, age=20.6 +/- 1.3 years) at a mean of 31.0 +/- 16.3 months following ACLR participated in this study. Participation restrictions in activities of daily living and sports were measured by the combined scores of the Knee Outcome Survey Activities of Daily Living Scale and Sports Activity Scale. The status of knee structures was assessed by determining the number of previously injured structures in the knee and the time from the most recent ACLR to testing. Performance-based activity limitations were assessed with the single leg hop for distance test. Impairments included isokinetic quadriceps function and anterior tibiofemoral joint laxity. Forward stepwise regression analysis revealed that while the number of injured knee structures alone accounted for 47% of the variability in patient-reported participation restrictions, the combination of the number of injured knee structures, time from ACLR, and the hop index provided the most effective estimate of participation restrictions. Isokinetic quadriceps function and KT-1000 side-to-side differences were not entered into the regression model and were not significant predictors of participation restrictions. We recommend that clinicians use caution in assuming that isokinetic quadriceps function and anterior tibiofemoral joint laxity provide an effective estimate of participation restrictions.