Problems associated with in vitro fertilization of horses were the subject of the present review. The paper presents the intracytoplasmic sperm injection (ICSI) technique. Oocytes for in vitro fertilization can be obtained either from living or slaughtered mares and then cultured. Afterwards they are washed and only those containing 1 polar body are used for microinjection. All kinds of spermatozoa (heads, immobile spermatozoa, dead and abnormal) can be used. Several foals have been born in the USA, Europe and Australia after in vitro fertilization. The technique can be successfully applied in breeding programs which accept stallions with low volume or motility spermatozoa.