To summarize the existing experience with the use and success rate of assisted reproductive techniques (ART), in particular testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI), in Klinefelter patients. A systematic review of the literature, including all published case reports to date. Thirty-nine reported successful pregnancies fathered by nonmosaic Klinefelter patients. The overall risk of transmitting a chromosomal abnormality to the offspring of Klinefelter patients. In nonmosaic and mosaic Klinefelter patients, chromosomally normal sperm cells can be extracted from testicular tissue and used for ICSI. The application of ART to Klinefelter patients can be recommended as a method to achieve reproduction in this selected infertility patient cohort.