Ninety-one infants and children, aged 0 days to 12 years, who received 93 hearts from donors aged 2 days to 24 years between November 1985 and September 1990 were retrospectively studied. Forty-three children were less than 1 month of age; 31 children were between 1 month and 6 months of age, and 19 children were between 6 months and 12 years of age. The donor heart ischemic time ranged from 51 minutes to 8 hours 17 minutes (mean, 4 hours 2 minutes). Fifty-one hearts had an ischemic time of less than 4 hours (group 1), and 42 hearts, more than 4 hours (group 2). No significant difference was noted in the age of donor or recipient or in donor/recipient weight ratio. No correlation was found between ischemic time and number of primary graft failures between groups. Inotropic support was required for 3.9 +/- 3.3 and 5.2 +/- 3.7 days for group 1 versus group 2 (not significant). Ventilator status was the same between the groups. A significant decrease of posterior wall movement in diastole (p < 0.01) occurred among patients of group 2 at 1 week after transplantation, but no difference was found between groups at 2 weeks, 1 month, and 3 months after operation. Posterior wall movement of group 2 heart grafts recovered completely by week 2. No difference was noted in the fractional shortening between the groups; but in both groups, fractional shortening significantly increased from week 1 to week 2. We conclude that ischemic times up to nearly 8 1/2 hours are well tolerated by donor hearts used in pediatric transplantation.