Intravaginal culture (IVC) is a new technique elaborated by the authors for the fertilization and culture of human oocytes. Its principle consists of fertilization and early development of the eggs in a closed, air-free milieu without the addition of CO2. One to five ovocytes are deposited in a tube completely filled with 3 ml of culture medium less than 1 hour after their recovery, with 10,000 to 20,000 spermatozoa per ml previously prepared. The tube is then hermetically closed and it is placed in the maternal vagina and held by a diaphragm for incubation for 44 to 50 hours. After this time, the content of the tube is examined and embryos are transferred to the uterus. In the first 100 consecutive punctures, 22 clinical pregnancies were obtained: 17 deliveries, 3 spontaneous abortions, and 2 tubal pregnancies. Also, a randomized study comparing IVC to in vitro fertilization (IVF) was done (160 cycles) and no statistically different cleavage, transfer, or pregnancy rate was seen between IVC and IVF. By simplifying the laboratory manipulations, this technique decreases the cost of IVF and permits its standardization and diffusion. It creates a psychologic comfort permitting active participation of the mother in this stage of embryo development. Also, the use of this technique may give greater knowledge of human gamete metabolism and of the physiology of reproduction.