In an attempt to establish reference values for sperm morphology in wild red deer, genital tracts were collected from thirty-six 3-11 years old free-ranging, wild red deer stags (Cervus elaphus L) shot down during 3 consecutive mating seasons (1996-1998) at three different environmental regions of Poland, defining two major ecotypes: (i) highland (outer eastern Carpathian range, Bieszczady mountains) and, (ii) lowland (Mazuria and Pomerania) and studied within 4.5h-49h after death for testis (T), epididymides (E) and vesicular gland (VG) variables. Spermatozoa collected from the E-cauda were examined for motility and morphology (light and electron microscopy levels). Both T size and weight and VS-weight differed with age (P<0.05-0.01) while habitat influenced T size and weight (P<0.01) a well as sperm motility (P<0.05). Neither sperm numbers nor morphology showed significant differences, mostly owing to

the large variation recorded among stags (range 1-72%). Domain-grouped sperm morphological deviations were <5%, the mean total proportion of abnormal spermatozoa ranging 7.2-17.5%. Although variation was present, the values ought to be used as reference for spermiogrammes.