Chondromodulin-I (ChM-I) is an angiogenesis inhibitor isolated from fetal bovine cartilage. Here, we report the nucleotide sequence of chicken ChM-I cDNA. Chicken mature ChM-I had a significantly larger N-terminal hydrophilic domain than its mammalian counterparts. Chicken embryos expressed multiple transcripts (3.3, 2.0 and 1.7 kb in size) due to the alternative utilization of polyadenylation signals, whereas only the 1.7 kb transcripts were detected in mammals. Although confined to cartilage and eye at a later stage of development, whole-mount in situ hybridization revealed the expression of ChM-I mRNA in somites, heart, bronchial arches, roof plate, retina and limb buds. The expression pattern of the gene suggests a role for ChM-I in the morphogenesis during embryonic development.