Poly(ADP-ribose) polymerase (PARP) plays an important role in DNA repair and other cellular processes. Tumor cells with defects in DNA repair pathways are highly sensitive to the inhibition of PARP activity. So far, four PARP inhibitors (PARPis) have been approved for the treatment of several types of cancer with BRCA mutations; moreover, PARPis have also shown therapeutic potential in treating non-oncological diseases. Therefore, many young patients will be exposed to PARPis and may need to be maintained on these treatments for a long duration, many of whom are of reproductive age. However, the impact of PARPis on ovarian and testicular function remains unclear. In this review, the effects of PARPis on the gonads, fertility, and their mechanisms are discussed, highlighting the significance of further investigation into gonad monitoring indices and protective approaches related to PARPis treatment.