A study to assess the efficacy of vardenafil, taken as a tablet both nightly or 'as needed' (immediately before intended sexual activity) compared to placebo, to evaluate its tolerability and if it can help in recovery of erections after a nerve sparing radical prostatectomy.

Inclusion Criteria:

At Screening

• Males 18-64 years of age
• Scheduled to undergo bilateral nerve-sparing radical retropubic BNSRRP, as selected according to the investigator's usual clinical practice
• Surgery scheduled within about 1 month of screening (Visit 1)
• Expressed an interest in resuming sexual activity as soon as possible after prostatectomy
• Heterosexual relationship
• No pre-operative erectile dysfunction:
• International Index of Erectile Function (IIEF) Erectile Function Domain Score score EF domain =26 at screening without any therapy/devices for improvement of erections
• No perforation of the prostate capsule by tumor

At Randomization:

Before being randomized subjects must still be meeting all Screening Inclusion Criteria, as well as the following criteria:

• bilateral nerve-sparing during the retropubic prostatectomy documented on the operating report
• BNSRRP occurred within approximately 1 month post screening (Visit 1)
• No perforation of the prostate capsule by tumor:

No positive tumor margins confirmed after surgery: =T2 stage on pathology report from the surgery

Exclusion Criteria:

• Subjects who are taking nitrates or nitric oxide donors
• Subjects who are taking the following inhibitors of cytochrome P 450 CYP 3A4: very potent HIV protease inhibitors (ritonavir, indinavir), the anti-mycotic agents itraconazole and ketoconazole (topical forms are allowed) or erythromycin
• Known hypersensitivity to Vardenafil
• Presence of significant penile anatomical abnormalities (e.g. penile fibrosis or Peyronie's disease)
• History of retinitis pigmentosa
• Unstable angina pectoris
• History of myocardial infarction, stroke or life-threatening arrhythmia within the prior 6 months
• Severe chronic or acute liver disease
• Symptomatic postural hypotension in the past 6 months
• NYHA Class III or IV heart failure
• Life expectancy <3 years
• Clinical diagnosis of significant untreated sleep apnea or working night shifts (e.g. 23:00h to 7:00 h)
• Anti-androgens use
• Residual prostate cancer, or requirement for radiotherapy or ADT after surgery