PURPOSE: Intracavernous injection (ICI) was once the cornerstone of treatment for erectile dysfunction (ED). This study was designed to investigate how the treatment of ED has changed since introduction of oral sildenafil. MATERIALS AND METHODS: In a total of 574 new ED (mean duration 2.9 years) patients with a mean age of 52.6 11.8 years, associated diseases, the cause and duration of ED, and the treatment used initially and after 6 months were investigated. RESULTS: The ED was psychogenic in 40.7% of the men. The most common cause of organic ED was vascular (18.1%) followed by diabetes (15.9%). The associated diseases were hypertension (19.9%), diabetes mellitus (16.5%), trauma and surgery (5.5%), endocrinologic (4.7%), coronary artery (1.6%), and hypercholesterolemia (1.1%). The initial treatment modality was an oral sildenafil in 68.7%, ICI in 11.3%, testosterone replacement in 2.7%, implantation of penile prostheses in 0.8%, and wait and see in 16.5%. Six months later, excluding the patients lost to follow-up, 73.4% of the patients were using oral sildenafil and 20.5% were using ICI. CONCLUSIONS: Oral sildenafil has largely replaced intracavernous injection for the initial treatment of erectile dysfunction.