Thirty-five patients were treated for Type III fractures of the intercondylar eminence of the tibia and were followed up for two to seven years. There were 20 Type IIIA fractures and 15 Type IIIB fractures. The avulsed fragment was reduced by operative arthroscopy and maintained either by extension and immobilisation in a cast or by crossed percutaneous pin fixation. Involvement of the medial collateral ligament or lateral meniscus was confirmed by valgus stress radiographs and by arthroscopy. Primary surgical repair through a separate incision was required in a significant number of patients. At follow-up, few patients suffered ligamentous instability, lack of extension, atrophy of the quadriceps, pain or effusion, and symptoms were minimal. Patients requiring surgical repairs of collateral ligaments or of peripheral detachments of the meniscus generally required a longer period of rehabilitation. Arthroscopic reduction and percutaneous pin fixation provided an effective treatment and significantly decreased the time spent in hospital and the morbidity experienced after alternative treatments.