Bves (blood vessel/epicardial substance) is a transmembrane protein postulated to play a role in cell–cell interaction/adhesion. It was independently isolated by two groups as a gene product highly enriched in the developing heart. Disagreement exists about its expression during development. Most notably, the expression of Bves in non‐muscle cells is disputed. Determining the expression profile of Bves is a critical initial step preceding the characterization of protein function in development and in the adult. We have generated new monoclonal antibodies against mouse Bves and used these immunoreagents to elucidate Bves expression in development. As expected, we detect Bves in myocytes of the developing heart throughout development. In addition, skeletal and smooth muscle cells including those of the coronary system express Bves. Finally, specific, but not all, epithelial derivatives of the three germ layers are stained positively with these monoclonal antibodies. Protein expression in cultured epithelial and muscle cell lines corroborate our in vivo findings. Taken together, these results demonstrate the expression of Bves in a wide range of epithelial and muscle cells during mouse embryogenesis and indicate a broad function for this protein in development, and show that these newly generated reagents will be invaluable in further investigation of Bves. Developmental Dynamics 235:1701–1708, 2006. © 2006 Wiley‐Liss, Inc.