The vomeronasal organ (VNO) is a tubular chemoreceptory organ which detects environmental pheromones and is essential for mammalian normal reproductive activity. A sensitive chemoreceptory neuroepithelium lines the concave VNO wall and the opposite, convex wall is lined by a seudostratified, receptor-free epithelium. The secretion of the Jacobson glands (JG) -tubuloacinary glands lying in the lamina propia of the VNO - is essential for pheromones contacting vomeronasal organ chemoreceptors. Tubuloacinary glands lying in the connective tissue of the nasal septum mucosa (Bowman glands), can be classified as ventral and dorsal, according to their location. Positivity to PAS and Alcyan blue reactions and androgen receptor immunolocalization was evaluated with a semiquantitative system (0,1, 2 or 3 crosses) in JG, ventral Bowman glands (VBG), dorsal Bowman glands (DBG), sensitive chemoreceptory neuroepithelium (Ne), receptor-free epithelium (RFE) and nasal septum respiratory epithelium (RE) histological slides of male rats at 5, 15, 25 and 35 days of age. The VBG and JG were intensely positive to PAS reaction since 5 days of age, and weakly positive to Alcyan blue reaction (AB) since 15 days of age, but not at 5 days of age. Both JG and VBG were strongly positive to androgen receptor immunolocalization at all ages studied (15, 25 and 35 days of age). DBG were always negative to both PAS and AB reactions. The NE and the RFE and nasal mucosa luminar epithelium were negative. To our knowledge, this is the first report of androgen receptor (AR) immunolocalization in the vomeronasal organ and the nasal septum mucosa. The present results also suggest an influence of androgens on the mechanism of pheromones contacting with the Ne of the VNO through regulation of the Jacobson glands secretion