Abstract: There have been numerous studies which demonstrate a relatively high incidence of gallstones in adult solid-organ transplant recipients receiving cyclosporin A (CsA) immunosuppression. The purpose of the present study was to investigate our experience with cholelithiasis in babies and children undergoing heart transplant (HTx). From May 1985 to December 1998, 311 neonatal and pediatric cardiac transplants were performed at our institution. Routine abdominal ultrasound was performed at 3 months, 1 yr, and bi-annually thereafter on all transplant recipients. Asymptomatic or symptomatic gallstone development was detected during abdominal ultrasound in 10 of 311 patients (3.2%). Eight of these 10 patients (80%) were transplanted when younger than 3 months of age. Eight per cent of all infants transplanted at < 3 months of age developed cholelithiasis (p < 0.05 compared to older age at HTx). Fifty per cent of gallstones were detected and treated within 6 months post-HTx, while the remaining 50% of patients with gallstones underwent cholecystectomy 3–6 yr later. Only 20% (two of 10) had symptoms of cholelithiasis/cholecystitis. Five patients (50%) underwent laparoscopic cholecystectomy. Only one patient older than 1 yr of age, who was symptomatic, underwent open cholecystectomy. There were no complications from surgery. There were no differences in liver function tests or cholesterol levels in transplant recipients with or without gallstones, and all mean values were within normal limits. Hence, although the incidence of pediatric post-transplant cholelithiasis in infant and pediatric heart transplant recipients is low, almost all occurrences are associated with HTx during early infancy and, because of this, patients in this group should be routinely screened. Laparoscopic or open cholecystectomy are extremely well tolerated and we recommend that surgery be performed when cholelithiasis is found in pediatric heart treatment patients.