Many drugs have been reported to impair semen parameters, leading to temporary or persistent infertility. Therefore, potential fathers may be concerned about the effect of medications on fertility. We searched the MEDLINE database of articles in English combining key terms including “male infertility,” “spermatogenesis,” “fertility,” “drug effects,” and “dermatology.” Administration of methotrexate and finasteride has resulted in severe oligospermia and reversible infertility. Ketoconazole has had negative effects on sperm motility and testosterone production. Few individual case reports and a limited number of studies have demonstrated negative effects of tetracyclines, erythromycin, chloroquine, glucocorticoids, spironolactone, and antihistamines on fertility. It is important to counsel male patients when appropriate about the reversible negative effect on fertility when taking methotrexate and finasteride, and the adverse effect of ketoconazole. Patients may be reassured that taking oral retinoids, cyclosporine, azathioprine, and tumor necrosis factor alpha inhibitors should not affect their fertility.