Four patients complaining of erectile dysfunction and using tobacco or propranolol were examined with penile blood pressure measurements and Doppler recordings, calculating the penile acceleration ratio (PAR). After a change in regimen, erectile capacity was restored, PAR returned to normal, and blood pressure measurements revealed increased systolic penile blood pressure in three patients. The changes, especially in PAR, indicate a marked penile vascular reaction during smoking and beta-blocking treatment in these men.