We evaluated 22 men 22 to 70 years old with previous acute epididymitis by pressure-flow study 3 to 12 months after the inflammation had resolved. Nine healthy men 20 to 62 years old were evaluated as controls. The patients had no symptoms from the lower urinary tract except for 2 men with slight prostatism. The maximum intravesical and maximum voiding pressures were elevated significantly in the patients compared to the controls (p less than 0.05). In most patients and in all of the controls the maximum urinary flow rates were within the normal range according to age. Because of the frequency of high voiding pressures in patients with previous acute epididymitis, this condition may be a pathogenic factor by promoting urethrovasal reflux. The high voiding pressures may be transmitted to the proximal urethra or in cases of a narrow and rigid bladder neck they may produce increased turbulence in the urine stream.