This study presents the five-year follow-up-results (range 56 to 63 months) of 76 of 119 patients who had had arthroscopically assisted reconstruction of the anterior cruciate ligament with use of the central third patellar tendon for acute rupture (19 patients = group A) or chronic ACI insufficiency (57 patients = group B) between may 1991 and october 1993 in the Department of Trauma Surgery University Hospital Ulm. The average Lysholm knee score was 94.6 points (group A = 97.1,group B = 93.8 points). The IKDC-score rated 21.10% of all patients as A (group A = 31.6%, group B = 17.5%), 57.9% as B (group a = 52.6%, group B = 59.6%), 19.7% as C (group A = 15.8%, group B 21.7%) and one patient of group B as level D. 9 patients (= 11.8%, group A = 21.1%, group B = 8.8%) showed up to 10 degree extension loss (compared with contralateral kneel, one patient of group A (1.3%) more than 10 degree. A flexion loss up to 15 degree was seen in 12 patients (= 15.8%, group A = 21.1%, group B = 14.0%), of more than 15 degree in 3 patients (= 3.9%, group A = 5.3%, group B = 3.5%).The average KT-1000-side-to-side difference was 2.5 mm with 90 N (group A 2.4 mm,group B = 2.5 mm), 2.8 mm with 133 N (group A = 2.7 mm, group B = 2.8 mm) and 3.2 mm (both groups) for manual maximum. There was no statistically significant difference in quadriceps and hamstring isokinetic strength (Cybex) of operated vs. unaffected limb for 60 /s as well as 240 /s. X-ray analysis showed arthrotic signs of minimum one compartment in 22.3% of all patients (group A = 26.3%, group B = 21.1%). In summary, we found better long-term results of IKDC-score in patients with autogenous patellar tendon graft for acute ACL-rupture vs. chronic ACL insufficiency. In Lysholm knee score and KT-1000 arthrometric measurement we just saw little but not statistically significant differences between the two groups. The isokinetic strength of quadriceps and hamstring were similar between operated vs. unaffected limb as well as between group A and B.