Phosphodiesterase type 5 (PDE5) inhibitors are considered as first-line therapy in the management of patients with erectile dysfunction (ED). ED is defined as “the persistent inability to attain and maintain a penile erection sufficient to permit satisfactory sexual intercourse” and is common condition in men. The first aim of this study was to investigate the efficacy and safety of 10mg tadalafil vs vardenafil 10 mg in a general population of men with ED. The second was to choose the best PDE5is for the individual patient with ED. A 16-weeks, DBR, parallel-group study conducted at Tirana, Albania. Eligible participant were men aged ≥ 18 to ≤ 70 years with ED for at least 6 months, 3 attempts at sexual intercourse on 3 separate days, not during continuously day, which were unsuccessful. Patients received 12 weeks, either 10mg tadalafil or 10mg vardenafil. Primary measures were the erectile function domain of the International Index of Erectile Function (IIEF-EF) and the Sexual Encounter Profile questions 2 and 3 (SEP2,SEP3).Secondary measures included SEP diary questions 1, 4, 5,and 6; the Treatment Satisfaction Scale; and the Global Assessment Question.