The appearance and differentiation of papillae on dorsal and lateral surfaces of human embryonic and fetal tongues, at various developmental ages, were studied by scanning electron microscopy. Formaldehyde and phosphate buffer fixation provided satisfactory preservation. At 8–9 weeks, the anterior two-thirds of the tongue showed no obvious signs of papillae. In contrast, just anterior to the sulcus terminalis rounded elevations were seen, suggesting initial signs of circumvallate papillae. At 10–13 weeks, the distribution and shape of elevations on the anterior two-thirds of the tongue indicated the beginning of fungiform papillae. Openings located on the dorsal surface of many of these fungiforms contained an amorphous central structure projecting out of the papilla. First signs of foliate papillae were seen at 10 weeks. At 15–18 weeks, fungiform and filiform papillae were recognized, although sometimes their borders were obscured by scaling epithelial cells. At 23–26 weeks, all papillae exhibited their adult form.