In this study, we measured functional outcomes of patients treated arthroscopically with microfracture for full-thickness traumatic defects of the knee. A case series of patients with 7 to 17 years' follow-up. Between 1981 and 1991, a total of 72 patients (75 knees) met the following inclusion criteria: (1) traumatic full-thickness chondral defect, (2) no meniscus or ligament injury, and (3) age 45 years and younger (range, 13 to 45 years). Seventy-one knees (95%) were available for final follow-up (range, 7 to 17 years). All patients completed self-administered questionnaires preoperatively and postoperatively. The following results were significant at the P <.05 level. Significant improvement was recorded for both Lysholm (scale 1 to 100; preoperative, 59; final follow-up, 89) and Tegner (1 to 10; preoperative, 3; final follow-up, 6) scores. At final follow-up, the SF-36 and WOMAC scores showed good to excellent results. At 7 years after surgery, 80% of the patients rated themselves as "improved." Multivariate analysis revealed that age was a predictor of functional improvement. Over the 7- to 17-year follow-up period (average, 11.3 years), patients 45 years and younger who underwent the microfracture procedure for full-thickness chondral defects, without associated meniscus or ligament pathology, showed statistically significant improvement in function and indicated that they had less pain.