The application of artificial insemination technology within the red deer and fallow deer farming industries is in its infancy. However, its future potential is enormous, particularly in relation to genetic improvement programmes and international exchange of genetic material. This paper reviews the present state of such technology for these two species by discussing the major components of oestrous synchronisation, semen collection/cryopreservation and insemination techniques. Artificial oestrous synchronisation overcomes problems associated with the detection of natural oestrus. Synchronisation can be achieved through the administration of progestagens or strategic administration of prostaglandin analogues. Most studies have investigated the use of the controlled internal drug release (CIDR) device, with 12-14 day insertion plus 200-250 IU pregnant mares' serum gonadotrophin (PMSG) at device withdrawal (red deer) or 14 day insertion alone (fallow deer) being the more common treatment regimens within the natural breeding season. Administration of cloprostenol on Days 13-14 of the oestrous cycle is also highly effective in fallow deer. Future studies need to refine synchronisation regimens to increase oestrous synchrony. Semen collection, which is under seasonal constraints, is mainly by electro-ejaculation, with semen processed for cryopreservation using standard techniques. The development of artificial vagina (AV) collection methods holds promise for safer and more efficient semen collection from deer. Transcervical access to the uterine lumen has proven difficult in red and fallow deer. Presently, most fixed-time inseminations are performed per vaginam (intravaginal or intracervical) or laparoscopically (intrauterine). Conception rates to per vaginam inseminations ( (20-80) X 10(6) motile spermatozoa) at approximately 48 h after CIDR device withdrawal have been highly variable and generally low (less than 40%) for both species, with a tendency towards better rates (40-60%) with double inseminations (44 and 68 h) in red deer and higher concentrations of motile spermatozoa (more than 100X10(6)) for fallow deer. Conception rates to laparoscopic intrauterine inseminations ((1040)X10(6) motile spermatozoa) at 54-56 h (red deer) or 65-70 h (fallow deer) after CIDR device withdrawal have been more consistent and generally higher (60-70%) for both species.