A 33-year-old patient became pregnant two years after transplantation of a cadaver kidney and continuous cyclosporine administration. An uncomplicated spontaneous delivery of a healthy boy weighing 3360 g took place in the 40th week. Cyclosporine was demonstrated in umbilical cord and neonatal blood and in the mother's milk, but not in amniotic fluid. Because mother's milk contained one sixth the concentration of cyclosporine in maternal blood, the mother was dissuaded from breast feeding.