This study examined the anatomical and histological characteristics of tubular genital organs of 51 adult female red brocket deer in the wild in different reproductive stages, collected by rural hunters in the north-eastern Peruvian Amazon. The infundibulum was characterized by a large diameter and the presence of a highly folded and ciliated epithelium, and the isthmus has a growing secretor epithelium and a thicker muscular layer. Whereas ciliated cells are more frequent in the infundibulum, epithelial secretory cells showing abundant apical secretory blebs are more frequent in the isthmus. In non-pregnant females in luteal phase, the endometrium transforms from a proliferative to a secretory type, showing a significant proliferation of endometrial uterine glands. The red brocket deer has four large circular folds in the cervix. The epithelium of the cervix is composed primarily of secretory cells. In pregnant females, the lumen of the endocervical canal is occupied by abundant mucous secretion. All pregnant females had one embryo or fetus, with a fetal sex ratio of 54.0% females to 46.0% males. This species has a cotyledonary, syndesmochorial and partially deciduate placenta, with 6-7 dome-shaped caruncles per female. The red brocket deer does not present a true cornification of the vaginal epithelial cells, and no vaginal epithelial pattern was determined according the reproductive state of the female. © 2012 Blackwell Verlag GmbH.