BAY38-9456, 5/10/20mg, vs.Placebo in Erectile Dysfunction

Inclusion Criteria: * Men with heterosexual relationships aged 18 - 64 years suffering from ED for more than 6 months according to the NIH Consensus Statement (i.e. inability to attain and/or maintain penile erection sufficient for satisfactory sexual performance). * At least 4 attempts at sexual intercourse (according to the question in the subject diary) on 4 separate days during the 4-week untreated baseline period. At least 50% of attempts during this period had to be unsuccessful according to the subject diary. Exclusion Criteria: * Presence of penile anatomical abnormalities (eg penile fibrosis or Peyronie's disease) that in the investigator's opinion would significantly impair sexual performance. * Primary hypoactive sexual desire.-Spinal cord injury-History of surgical prostatectomy (transurethral interventions not excluded). * Unstable angina pectoris. * History of myocardial infarction, stroke or life-threatening arrhythmia within the prior 6 months. * Uncontrolled atrial fibrillation/flutter at screening visit (ventricular response rate \>100 BPM).