A total of 145 cases with Erectile Dysfunction(ED)have been evaluated by the Ogura Shinryosho Clinic in Tokushima City, Japan. The effectiveness of Sildenafil, defined here as intercourse satisfaction(V), was quantified through a pre-treatment and a post-treatment self-report measurement called the IIEF 5 Questionnaire. The structural components that contribute to intercourse satisfaction(V)were also evaluated. Confidence(I),ability to penetrate(Ⅱ), frequency of intercourse(Ⅲ),and maintenance of an erection(Ⅳ)were predicted to contribute to intercourse satisfaction. Results of this study show that 52.4% of the patients(n=145)achieved a normal level of intercourse satisfaction(indicated by a score of 22-25 on the IIEF 5). The patients’collective score improved from 9.84 to 20.63 on the IIEF 5 and was statistically significant(p<0.000). Numbers needed to treat(NNT)was found to be 2 patients. The structural components found to contribute to intercourse satisfaction(V)through multiple linear regressions were frequency of intercourse(Ⅲ), maintenance of an erection(Ⅳ), and ability to penetrate(Ⅱ). Confidence(I)did not contribute to intercourse satisfaction(V). No severe adverse events to Sildenafil were observed, but some minor side effects included flushing(4.14%), headaches(2.07%), heart palpitation(0.69%), and dyspepsia(0.69%)