Using an organ bath model with porcine cavernosal tissue strips and an in vivo monkey model we demonstrated that abanoquil, a novel alpha adrenoceptor antagonist, is able to relax contracted tissue strips and induce erectile response when injected intracorporally. The erectile response in the monkeys was not dose-related and compared to the effect of papaverine injections, abanoquil induced a lower level of tumescence and rigidity. Hence, abanoquil might be useful as a facilitator of erection in the pharmacological treatment of erectile dysfunction. International Journal of Impotence Research (2000) 12, Suppl 1, S37-S40