Donor-site complications, specifically chest wall deformities and thoracic scoliosis, occurring after harvest of costal cartilage grafts are presented and discussed. The cases of 18 patients (12 male and 6 female), who underwent costal cartilage grafts for microtia reconstruction from 1975 to 1993, were reviewed for donor-site complications using radiography and physical examination. Ribs from which costal cartilage had been harvested showed increased inward bowing on radiographs in 16 of 32 donor sites. The frequency of rib deformity in donor sites was 20.0 percent when cartilages were harvested from patients older than 10 years of age, whereas it was 63.6 percent in patients younger than 10 years old. This difference was statistically significant (p = 0.027, Fisher's exact test), although only 32 grafts were performed in 18 cases. The upper ribs demonstrate a higher incidence of deformity than lower ribs. Thoracic scoliosis was found in 4 of 16 cases. The biomechanical impact of these deformities was considered because of respiratory movement of the thorax and injury to the germinal growth center of the ribs. We recommend delaying costal cartilage grafts for as long as possible, leaving the costochondral junction intact to minimize chest wall deformity and thoracic scoliosis.