Culture and sensitivity testing of specimens obtained by percutaneous and intraoperative needle aspiration of the epididymis have been of clinical importance in choosing proper antimicrobial therapy in selected patients with acute non-venereal epididymitis. We have found aspiration cultures to be valuable in patients 1) with indwelling urethral catheters, 2) who fail to respond to initial antimicrobial therapy, 3) who have epididymitis found on surgical exploration for torsion of the teticle and 4) with recurrent epididymitis in whom the etiologic agent is uncertain.