Retrograde ejaculation as a complication of diabetes is unappreciated, unrecognized, and for the most part, clinically unknown. This paper records five such cases, documents this syndrome as a diabetic autonomic neuropathic manifestation, and indicates the sequential developments in relation to its pathogenesis. The most common cause of retrograde ejaculation is transurethral resection of the prostate, but it has been noted in inflammation, trauma, and congenital malfunction of the posterior urethra. With specific import in interpretation of our data, it is significant that retrograde ejaculation has been observed as a common accompaniment of bilateral sympathectomy in the surgical therapy of essential