In vertebrates, Bmps (bone morphogenetic proteins) play critical roles in establishing the basic embryonic body plan and are involved in the development of a large variety of organs and tissues. To study the evolution of Bmps, we isolated cDNAs for three members of the zebrafish Bmp gene family: Bmp2a, Bmp2b and Bmp4. The deduced amino acid sequences of Bmp2a and Bmp4 consist of 386 and 400 aa, respectively and show high homologies to their counterparts in mouse, chick and Xenopus. The deduced Bmp2b aa sequence consists of 411 aa and the mature protein shows 88% and 86% identities to zebrafish Bmp2a and Bmp4, respectively. The expression of the mRNA of these three genes has been analyzed by whole mount in situ hybridization and RT-PCR. Areas of zebrafish Bmp2 and Bmp4 expression suggest evolutionary conserved mechanisms of Bmp2/4 dependent differentiation between lower and higher vertebrates.