Thirteen naturally mated rhesus monkeys were subjected to laparotomy on days 12-18 of the menstrual cycle and a fertilized egg was recovered from the oviducts of each. Individual eggs were returned to the contralateral oviduct or to the uterus of the donor monkey within 30 min of recovery. A male baby born in Nov., 1975 is fit and well and current pregnancies appear to be progressing normally. The techniques employed apparently have not adversely affected either the eggs or the conditions for conception. The results also prove that the environment provided by the contralateral oviduct, away from the immediate influence of the corpus luteum, is adequate for the survival of the embryo.