Zinc finger proteins (Zfp) are members of a multigene family encoding Zn mediated nucleic acid binding proteins. They have been isolated from various organisms including yeast, Drosophila, Xenopus mouse and human. All Zfp share the 28-30 amino acid long finger repeats containing conserved residues at specific positions. Some of these proteins have been identified as transcriptional regulatory factors. In this paper, we describe the isolation, DNA sequence determination and the expression pattern in developing embryos and adult tissues of 3 new members of the mouse Zfp. All of them are expressed as multiple transcripts. Unaltered level of mkr5 expression could be detected in 10-15 day whole embryo RNAs but its level started to decrease from day 16. In the adult animal, predominant expression was detected only in the ovary. In contrast, mkr3 and 4 were expressed at a constant level in all embryos and tissues tested. These data suggest the presence of both tissue specific and ubiquitious Zfp in the mouse.