Little is known about the influence of simple limbectomy on the growth of the acetabulum. An experimental study was carried out in ten monkeys divided into two groups: limbectomy only (Group A) and limbectomy with concomitant cartilage resection (Group B). After three years and four months postoperatively, monkeys were sacrificed. Excised joints were examined macro-and microscopically. Degenerative changes in the cartilage and hypertrophy in the joint capsule were noted in all five monkeys of Group B, and in none of Group A. The diameter of the acetabulum was significantly enlarged in Group B (longitudinal diameter: p<0.05, transverse diameter: p<0.01, Mann-Whitney's U test), compared with Group A and the contralateral hips as controls. There was no other significant difference in other soft tissue or osseous components, between two groups. Histologically, the injured limbus was healed with irregular and sparse fibrous tissue in both groups. Fibrillation in the superficial layer of the cartilage and cluster formation was frequently noted in group B, while normal appearance was noted in Group A. This study demonstrated that simple limbectomy dose not affect the growth of the acetabulum, but may cause degenerative changes if the adjacent acetabular cartilage was simultaneously injured.