ICSI for oocyte pathology may represent the solution in case of zona pellucida anomalies, deficiency of the oolemma fusion ability or absence of cortical reaction. These indications remain scarce and difficult to be displayed. A link could be shown by some authors between some oocyte morphologic anomalies and IVF fertilization failures which are overcome by ICSI. Other dysmorphic oocytes are associated with an impairment in cytoplasm function which results in a poor embryonic viability on which ICSI has no effect. When few oocytes are recovered (< or = 5) and the semen characteristics are not optimal, ICSI may rectified the decrease in fertilization rates obtained after classical insemination. Lastly, ICSI will become increasingly used in case of oocyte in-vitro maturation or freezing instead of classical IVF which is less efficient.