A new report in the journal Cancer looked at the cancer records of men attending fertility clinics in California.
Researches found those having trouble fathering a child were nearly three times more likely to be diagnosed with prostate cancer.
No ones sure what the connection might be or if there really is one at all.
Researchers say more work needs to be done to confirm the possible link. But if the results hold up they say it might make sense for infertile men to be screened for prostate cancer at an earlier age.