how long does sperm live in a woman? Upon ejaculation, sperm can live inside a woman's reproductive system for up to five days. This longevity is due to the protective environment of cervical mucus, which nourishes and safeguards the sperm. The actual fertilization window, however, is generally shorter, usually around 24 to 48 hours after ovulation. Factors like the timing of the menstrual cycle, sperm health, and the woman's reproductive health influence the chances of conception. Understanding these dynamics can be valuable for those trying to conceive or those seeking effective family planning methods.