The brush-tailed porcupine Atherurus africanus is an important source of meat for local people in tropical forested areas of Central Africa. Information on the biology of this species in free-ranging conditions is scarce. Data on its reproduction and productivity are essential to establish accurate management practices in the exploitation of this rodent. In order to provide data on the reproductive physiology and to assess the prolificacy of the brush-tailed porcupine in the wild, the structural and functional anatomy of the ovaries of free-ranging females were studied. Twenty-two female carcasses were obtained from various markets in Libreville, Gabon, between August 1995 and February 1997. Reproductive tracts were macroscopically examined for the presence of embryos or foetuses. The ovaries were embedded in paraffin wax or plastic and examined by light microscopy. The morphology and constituent cell types of the ovaries were similar to those described for other hystricognath rodents. All pregnant females had only one embryo or foetus and the number of corpora lutea (CL) per female was 19.9 ± 5.4 (mean diameter ± sd, 1709 ± 421 μm), including one CL of pregnancy (diameter, 4821 ± 1364 μm). Also, 8.9 ± 6.8 accessory CL per female in the pre-implantation and embryonic stages of pregnancy (diameter, 1629 ± 463 μm) were observed. The average active luteal volume was high (115.6 ± 73.5 mm3). The mean number of antral follicles in the adult females was 24.6 ± 9.9. The study confirms that the brush-tailed porcupine is a mono-embryonic species, as observed in captive breeding experiences, but polyovular, suggesting important ovum mortality. This unusual reproductive feature in a mammalian species gives this rodent a low reproductive productivity. Therefore, A. africanus could be more susceptible to the effects of hunting than generally thought.