The expression of some members of the TGFß family of genes in embryonic craniofacial tissue suggests a functional role for these molecules in orofacial development. In other systems, TGFß1 and TGFß2 have been shown to regulate cell proliferation and extracellular matrix metabolism, processes critical to normal development of the secondary palate. We have thus determined the amount and tissue distribution of both TGFß1 and TGFß2 in embryonic palatal tissue. Cellular extracts of murine embryonic palatal tissue from days 12, 13 and 14 of gestation were assayed for the presence of TGFß1 and TGFß2 by immunoprecipitation. Physiological levels, ranging from 0.05-20 ng/µg protein, of both growth factors were detected in all tissues examined. Immunostaining with antibodies directed against either TGFß1 or TGFß2 demonstrated the presence of these growth factors in palatal epithelium and mesenchyme early during palatal development (gestational day [GD] 12) a period characterized by tissue growth. On GDs 13 and 14, characterized by palate epithelial differentiation, immunostaining for both growth factors predominated in epithelial tissue. Immunostaining for TGFß1 and TGFß2 was also intense in mesenchyme surrounding tooth germs and in perichondrium. Chondrocytes and cartilage extracellular matrix did not stain for either TGFß1 or ß2. Combined with existing evidence for the presence of functional receptors for the transforming growth factor-ßs in the developing palate, these results provide rationale for studies designed to clarify a specific role for these signalling molecules in palate epithelial differentiation and/or epithelial-mesenchymal interactions.