Glucocorticoids are known to be teratogenic, and administration of these compounds during pregnancy produces cleft palate in the offspring. In the mouse, induction of cleft palate correlates with the level of palatal glucocorticoid receptor (GR) expression. In the present study, GR expression was evaluated in the developing palates of C57BL/6N mouse embryos on gestation days (GD) 12, 13, 14, and 15 by both in situ hybridization and immunohistochemistry. Chondrogenic regions strongly expressed GR. In different regions of oral and nasal epithelia localized patterns of expression were noted and may be related to differentiated state. Correspondingly, GR mRNA was expressed in epithelia and became regional in mesenchyme with abundant mRNA in regions of bone formation. GR localized initially within regions of active morphogenesis and subsequently within differentiating cells. This specificity of spatial and temporal expression supports the idea that GR is involved in regulation of regional growth and differentiation during palatogenesis.