Enalapril either alone or with a diuretic was administered to 15 children with various renal diseases and hypertension. Five were transplant recipients on multiple immunosuppressive agents. No adverse clinical or laboratory experiences were encountered except for mild proteinuria in two children, one of whom has evidence of chronic rejection. Enalapril effectively controlled blood pressure in all 15 patients when given once daily with or without food. Renal function improved in seven children. Six children are under excellent blood pressure control despite a reduction in the dose of enalapril. Two are currently on no medication, five require a diuretic, while one child is on an increased dose of enalapril.