Sperm samples were collected from the epididymides of 11 hunter-killed stags (Cervus elaphus hippelaphus) within 2 to 17 h post mortem in September 1991. Progressively motile spermatozoa were diluted and deep-frozen in tris-yolk extender by a procedure routinely used for bovine semen. The pre-freezing motility of spermatozoa from 6 stags was higher than 80%, while the sperm of 5 animals was found to be unsuitable for dilution. In the post-thawed sperm of six stags 40-50% of the spermatozoa showed progressive motility and the number of viable spermatozoa ranged from 8.6 to 26.7 x 10(6) per 0.25 ml straw. Two years later, three hinds were superovulated by the use of a progesterone-releasing intravaginal device (CIDR type G, Carter, Holt Harvey Plastic Products Group Ltd., Hamilton, New Zealand) for a period of 14 days and with follicle stimulating hormone (Folicotropin inj., Spofa, Prague). Each hind was inseminated artificially 60 h after the withdrawal of CIDR with thawed sperm injected into the uterus via the vagina. Seven days later the uteri were flushed out, as a result of which 3 early blastocysts + 1 ovum, 3 morulae + 4 ova, and 1 morula + 7 ova, respectively, were recovered from the three hinds. Deer embryos were frozen according to a glycerol-based freezing protocol. A further two years later two hinds were oestrus-synchronised with CIDR type G and 300 IU PMSG (Folligon inj., Intervet, NL), and two of the thawed embryos were transplanted into two recipient hinds 7 days after heat. One of these gave birth to a normal stag fawn in June 1996. This was the first deer born in Hungary from embryo transfer. The results obtained indicate that sperm from top stags shot in the course of hunting can prove useful for the preservation of genetic material or in the development of the farmed deer system.