Exposure to cyclophosphamide (CPA) for cancer treatment results in over-production of reactive oxygen species and oxidative stress thus affecting the DNA in male germ cell inducing sperm defects. Our goal is to assess the potential effects of Nigella sativa extract (NSE) and thymoquinone (TQ) on sperm and embryo quality following fertlization of sperm produced from germ cells which have been exposed to the damaging alkylating effects of CPA.