Intracytoplasmic sperm injection (ICSI) is a promising assisted fertilization technique that may benefit women who have not become pregnant by in-vitro fertilization. ICSI and subzonal insemination (SUZI) were used to treat couples who failed fertilization after standard IVF or who could not be accepted for IVF because too few motile spermatozoa were present in the ejaculate. This paper describes the outcome of 750 consecutive cycles of SUZI and ICSI. Different aspects of these novel assisted fertilization procedures are described: patient management, ovarian stimulation, semen evaluation and treatment, oocyte collection and preparation, SUZI and ICSI techniques, assessment of fertilization and embryo cleavage, outcome of embryo transfers and the evolution of the pregnancies.