Since the first reports of successful pregnancies in humans after treatment with intracytoplasmic sperm injection (ICSI), intensive investigations have focused on several important aspects of this form of assisted reproductive technology. In addition to the technical development of ICSI and increasing understanding of the biochemical and biophysical processes involved during fertilization after injection of an immobilized sperm, studies have aimed to define the indications for patients for a first-line ICSI treatment. One of the major concerns is of course the safety of the technique in terms of the health and reproductive life of the babies born after ICSI. The rhesus monkey is an excellent model to investigate all aspects of this micromanipulation technique. This article provides an evaluation of ICSI.