The quality of sperm DNA is very important in maintaining the reproductive potential of men. Sperm DNA is resistant to many types of insults that occur during its journey from the testis to time it reaches the oocyte for fertilization. During natural conception, a selection process occurs that allows only sperm with intact DNA to fertilize an oocyte. When assisted reproductive techniques (ART) are used, some or all of this selection process is bypassed. As a result, sperm with damaged DNA may fertilize an oocyte. Damage to sperm nuclear DNA negatively affects assisted and natural fertility. Increasingly, sperm DNA is being recognized as an independent measure of sperm quality that may have better diagnostic and prognostic capabilities than standard sperm parameters. This review summarizes the available evidence for the role of sperm DNA damage in assisted fertility. Two important facts are obvious from the available evidence: 1) men with spermatozoal DNA damage appears to have a decreased ability to father offspring, 2) spermatozoa with abnormal DNA can fertilize an oocyte, which may progress to a live birth. Infertile men who are planning to undergo ART procedures with their partner should have their sperm evaluated for DNA damage. The results of this evaluation may be used to counsel the couple about their chances for live birth and for genomic abnormalities in their offspring.