A case of premature triradiate cartilage closure secondary to a Gill acetabuloplasty performed at age 14 months is reported. The deficiency in acetabular development and failure of the pelvis to grow to its anticipated height is documented. A proximal femoral redirectional osteotomy and an innominate osteotomy performed near maturity improved femoral head coverage and hip biomechanics. Acetabuloplasties performed adjacent to the triradiate cartilage typically do not have any adverse effect on its function. Despite this low risk of injury to the triradiate cartilage after a Gill or Pemberton acetabuloplasty, long-term follow-up is recommended to observe acetabular development. Premature closure is most likely to occur if the bone graft used to maintain fragment displacement crosses the triradiate cartilage.