The two words that mean sexual dysfunction, impotence and erectile dysfunction (ED), express two different concepts. Impotence is a general male sexual dysfunction that includes libidinal, orgasmic, and ejaculatory dysfunction. ED is the inability to achieve or maintain an erection sufficient to allow satisfactory sexual intercourse and is part of the general male sexual dysfunction termed impotence that includes libidinal, orgasmic, and ejaculatory dysfunction. Uremic men of different ages report a variety of sexual problems, including sexual hormonal pattern alterations, reduction in or loss of libido, infertility, and impotence, conditioning their well-being status. In evaluating and treating sexual dysfunction, a nephrologist must consider factors involved in its pathogenesis, such as hypothalamic-pituitary-gonadal axis alterations, psychological problems related to chronic disease, secondary hyperparathyroidism, anemia, autonomic neuropathy, derangements in arterial supply or venous outflow, and the normal structure of cavernous body smooth muscle cells. The introduction of sildenafil to treat impotent patients has completely changed the approach to evaluating these subjects because this drug is considered an effective well-tolerated treatment for men with ED. In the past, we proposed an algorithm that gave the opportunity to explore the previously mentioned factors using such instrumental interventions as the nocturnal penile tumescence test, penile echo color Doppler, nervous conduction velocity, and cavernous body biopsy, addressed to prescribe needed surgical or medical interventions. The complexity of the proposed algorithm requires many diagnostic procedures and much time and economic resources to localize the pathological lesions responsible for ED. Because of the new oral drug sildenafil, we propose a new algorithm to test the possibility of obtaining an erection and classify patients as responders or nonresponders to the sildenafil test.