Erectile dysfunction (ED) and depression are highly prevalent conditions and frequently occur concomitantly in predisposed individuals. Men with ED and depression are also likely to have other comorbid conditions, including diabetes, hypertension, and heart disease. Because ED is also a common adverse effect of some medications for these conditions, patients are frequently noncompliant with treatment. Sildenafil citrate (Viagra) is effective in treating ED of a broad range of etiologies, suggesting that it may be equally beneficial in patients with ED that is associated with depressive symptoms and in those with ED resulting from serotonergic reuptake inhibitor (SRI) antidepressant treatment. We review the results of 3 randomized, placebo-controlled trials and a retrospective analysis of data pooled from 10 clinical trials that examine the efficacy of sildenafil in treating ED associated with depression and as an adverse effect of SRI treatment. The results suggest that sildenafil is efficacious as a first-line treatment for ED in men with untreated minor depression, in men with ED that is refractory to successful SRI treatment of depression, and in those whose depression was successfully treated but who developed ED as a consequence of SRI treatment. Given the complex interrelations among ED, depression, and other comorbid conditions, the key to proper management is a comprehensive evaluation, including sexual function, and an accurate differential diagnosis.