The mucocutaneous junction (MCJ) is a specific site located at body orifices such as the mouth, nose, eyelid, vulva, prepuce, and anus. The present study was conducted to reassess the MCJ in terms of 1) cytokeratin expression, 2) the distribution of immunoreactive cells, 3) nerves and their terminals, and 4) differences between near-term fetuses and adults. For cadaveric specimens after long-term preservation, cytokeratin 14 was useful for identification of the MCJ. In near-term fetuses, routine histology clearly demonstrated the putative MCJ due to transient, thick stratification of the squamous epithelium. This was most evident in the oral mucosa and less evident in the palpebral skin. In the anus and eyelid, the MCJ developed from highly proliferative epithelia of the anal sinus and meibomian gland, independent of the growing skin and mucosa. In elderly individuals, the MCJ was expanded in the nose and anus possibly as a result of mechanical stimuli, and was apparently connected to a hemorrhoid venous plexus. At the vulva and prepuce, a morphology intermediate between pseudostratified columnar and stratified squamous epithelia was evident. Except for the vulva and prepuce, corpusclelike nerve terminals were sandwiched between the dermal papillae and epidermis, whereas nerves arranged in parallel exhibited free ends beneath the mucosa. At the anus, the myenteric autonomic nerve plexus disappeared slightly orad to the MCJ. Langerhans cells were richly distributed in the skin stratum spinosum, while suppressive T lymphocyte clusters were present in the lamina propria mucosae. General rules and site-specificity of the MCJ were reviewed.