Abstract: The Intracytoplasmic Sperm Injection (ICSI) is a kind of micromanipulative technique in which a single sperm is directly injected into the ooplasm of a matured oocyte using a microscopic needle. It is a type of in vitro fertilization which is mainly used to treat severe male factor infertility in human. This procedure can bypass many barriers of fertilization including the process of sperm penetration through cumulus-corona cells, zona pellucida and oolemma during fertilization by directly depositing the sperm into the ooplasm. The introduction of ICSI in assisted reproduction has helped to investigate and understand the early events of fertilization such as sperm capacitation, the acrosome reaction and pronucleus formation. Like humans, domestic animals including goats, suffer from infertility or sub-fertility, which lowers their lifetime productivity and reduces the number of offspring that could be obtained from a sire or dam. The prevalence of this problem coupled with the desire of people to understand and subsequently control the reproductive processes has led to the development of novel assisted reproductive technologies (ARTs) like ICSI. It is one of the modern ART which can be used in livestock for the improvement and preservation of livestock genetics and the enhancement of reproductive efficiency. Till now, ICSI technique - one of the modern ARTs - has been successfully used in humans, rodents and other animals, especially in the cattle. The present study describes different aspect of ICSI including history, types of micromanipulative techniques, remodeling of fertilization process, oocyte activation and factors affecting outcomes of ICSI etc.