Pump cavernosometry, pharmaco-cavernosometry, gravity cavernosometry and the intracavernous pressure drop test are the most used tests for the diagnosis of venoocclusive dysfunction. To verify whether patients show equivalent results in each of these four tests, and to ascertain whether there is any influence of the sequence of the exams over the results, 123 male patients with erectile dysfunction, aged 21 to 82 years (mean 48), were evaluated. All were submitted to the four tests in randomized sequence. Two criteria were used to define the normal results of pump cavernosometry and pharmaco-cavernosometry, both based on patients with normal veno-occlusive function. The incidence of normal results varied from 6.5% in pump cavernosometry according to criterion I to 64.2% in pharmaco-cavernosometry according to criterion II. Results of the four tests agreed completely (all normal or all abnormal) in 43.9% of the patients when criteria I was used and 58.3% with criteria II. Incidence of normal results in each test did not vary according to the sequence in which the exams were done. Pump cavernosometry, pharmaco-cavernosometry, gravity cavernosometry and intracavernous pressure drop test did not show equivalent results for individual patients. Results were not influenced by the sequence of the tests.