Minoxidil is an antihypertensive vasodilator medication. It also slows or stops hair loss and promotes hair regrowth in some people. The exact way that this medicine works is not known. If hair growth is going to occur with the use of minoxidil, it usually occurs after the medicine has been used for several months and lasts only if the medicine continues to be used. Hair loss will begin again within a few months after minoxidil treatment is stopped. Adverse reactions include irritation of the skin, itching, contact dermatitis, and dryness of the scalp or flaking. An increase in the absorption of minoxidil from the scalp can occur in patients with damaged skin, leading to increased side effects. Minoxidil may cause serious side effects, including unwanted facial/body hair, dizziness, fast/irregular heartbeat, fainting, chest pain, swelling of hands/feet, unusual weight gain, tiredness, difficulty breathing especially when lying down. Erectile dysfunction (impotence) is the inability to get and keep an erection firm enough for sex. Erectile dysfunction can be caused by Physical causes, Hormonal disorders, Structural/anatomical disorder, drugs induced, and Psychological causes. We report a case of erectile dysfunction in a young patient not known to have any medical illness. In the view of unyielding clinical and laboratory evaluation, a drug-induced erectile dysfunction and decreased libido were suspected. Because of the use of topical minoxidil 5% over the last 4 months, and the improvement of the patient's condition, including palpitation, chest tightness, dizziness, and erectile dysfunction and libido after discontinuation of topical minoxidil 5%, and the recurrence of symptoms following it's re-administration, and after ruling out organic and psychogenic causes, we concluded that topical minoxidil 5% was the cause of the patient's clinical picture and should be considered as a cause of unexplained erectile dysfunction and decrease libido.