Objectives. Sildenafil has been demonstrated to be safe and effective in the treatment of men with erectile dysfunction. The role of sildenafil in treating women with sexual dysfunction has heretofore not been reported. The purpose of this preliminary study was to ascertain the response of postmenopausal women with self-described sexual dysfunction treated with sildenafil for 3 months. Methods. Thirty-three consecutive postmenopausal women with sexual dysfunction based on history were entered in this open-label, nonrandomized study. All patients received 50 mg of sildenafil. Efficacy was assessed at weeks 4, 8, and 12 using a newly developed 9-item, self-administered Index of Female Sexual Function (IFSF) and a global efficacy question ([GEQ] Did treatment improve your sexual function?). The IFSF quantifies the domains of desire, quality of sexual intercourse, overall satisfaction with sexual function, orgasm, lubrication, and clitoral sensation. Results. Of the group, 30 women (91%) completed the study and were available for follow-up at 3 months. Mean baseline IFSF score before therapy was 24.8 ± 9.8. Mean usage of sildenafil was 3.1 ± 1.4 times per week for the duration of the study. The IFSF score improved to 29.5 ± 7.6, 30.3 ± 8.5, and 31.4 ± 10.4 at 4, 8, and 12 weeks, respectively ( P = 0.25). Mean scores for questions 2 (lubrication), 8 (orgasm), and 9 (clitoral sensation) improved by 23.2%, 7.4%, and 31.3%, respectively, at 12 weeks. Seven women (21%) noted improvement on the GEQ. Overall, only 6 (18.1%) of 33 patients had a significant (more than 60% improvement in IFSF score) therapeutic response. Clitoral discomfort and “hypersensitivity” occurred in 7 women (21%), 3 of whom withdrew from the study. Other side effects, which did not result in withdrawal from the study, included headache (n = 5), dizziness (n = 4) and dyspepsia (n = 3). Conclusions. The data suggest that sildenafil is well tolerated in postmenopausal women with sexual dysfunction. Overall sexual function did not improve significantly, although there were changes in vaginal lubrication and clitoral sensitivity. The role of sildenafil in treating sexual dysfunction in various cohorts of women remains to be determined.