For 714 consecutive patients who underwent autogenous patellar tendon graft anterior cruciate ligament reconstructions we intraoperatively measured intercondylar notch width. We prospectively recorded height, weight, sex, and which patients subsequently tore their contralateral anterior cruciate ligament or the 10-mm autograft. The patients were divided into two groups based on notch width (group 1, < or = 15 mm; group 2, > or = 16mm. The mean notch width was 13.9 +/- 2.2 mm for women and 15.9 +/- 2.5 mm for men. There was no statistically significant difference in notch width between height groups for women or men. Analysis showed that, with height and weight as covariates, women had statistically significantly narrower notches than men. Twenty-three of 388 patients in group 1 and 4 of 326 patients in group 2 tore their contralateral anterior cruciate ligaments. Within groups, no statistically significant differences in contralateral tear rates existed between men and women. Once the men and women had reconstructions with equally sized 10-mm autografts, there was no difference in graft tear rate between groups or between men and women. Our results show that patients with narrower notches have a higher incidence of tearing their contralateral anterior cruciate ligament. After reconstruction with a 10-mm autograft, the incidence of graft rupture is the same for men and women.