Intracavernosal injection therapy has consistently produced erections in 60% to 70% of patients in whom it is tried. About 70% of patients enter long-term therapy and there is a dropout rate of 20% to 50% within the first year. The most effective current regimen is a mixture of papaverine-phentolamine and prostaglandin E1, that also seems to have a relatively low incidence of priapism and fibrous nodule formation. Patient education is vitally important to the success of a program. Patient satisfaction rates are high.