PURPOSE: To analyze the incidence and clinical and radiological results of anterior knee pain following tibial intramedullary nailing. MATERIALS AND METHODS: From January 1995 to April 1999, we retrospectively analyzed in 122 patients with tibial fracture who were treated by closed intramedullary nailing. All of 125 cases analyzed the age and sex distribution, mechanism of injury, fracture morphology, relationship of nail position on radiographs to knee pain and relationship of knee pain to the incision methods of patella tendon. Anterior knee pain was assessed with a 10-point analogue scale. Statistical analysis was performed using paired T-test. RESULTS: At a mean follow-up period of thirty-eight months(12-64 months), sixtynine( 56%) patients(70 of 125 knees) had developed anterior knee pain. Insertion of the nail through the patella tendon splitting incision was associated with a higher incidence of knee pain compared to the paratendon site of nail insertion(62% and 35% respectively). According to the radiological analysis, the mean extent of nail protrusion of 122 patients was -1.4mm and the average nail protrusion of 69 patients with knee pain was 1.3mm respectively. Nail removal resolved or improved the symptoms in 69%. CONCLUSION: Based on these data, we would recommend a parapatella tendon incision for nail insertion, and nail removal for those patients with a painful knee after bony union.