Tenascin is a glycoprotein of the extracellular matrix and is mainly expressed in association with a high proliferative and migratory activity. This characteristic has made it a successfully used target molecule in the treatment of glioblastoma. An application of anti-tenascin therapy concept in squamous cell carcinomas of the head and neck (HNSCC) mainly depends on the expression pattern of tenascin in a tumor type. In the present study, we analyzed the messenger (m) RNA and protein expression of tenascin in HNSCC tumors when compared to normal mucosa and determined its cellular localization and correlation with various clinical parameters, including tumor staging. In native tissue tenascin protein was localized in the entire extracellular matrix surrounding the tumor. Normal mucosa showed only a weak and interrupted basement membrane staining. In situ hybridization revealed a very faint tenascin mRNA signal in basal cells of normal mucosa and a strong signal in tumor cells. This tumor cell-specific expression of tenascin was confirmed at the protein level in HNSCC cultures. However, there was no correlation of tenascin expression with tumor staging or tumor cell proliferation. Our data clearly show that tenascin is selectively expressed in HNSCC and therefore could be useful for a therapeutic intervention in these tumors.