The odd-skipped (odd) gene encodes a zinc finger protein that represses other segmentation genes in the early Drosophila embryo. Though odd is initially expressed in a striped pattern that reflects its function within the segmentation hierarchy, it is also expressed in a variety of patterns during later stages of embryogenesis. To identify the cells and tissues that correspond to these latter patterns, we examined the distribution of the Odd protein at all embryonic stages. Our results indicate that Odd is a specific and persistent marker for subsets of cells in developing mesoderm, ectoderm, and neural tissue. We conclude that Odd is a useful tool for studying cell specification, cell migrations and morphogenetic movements during organogenesis of the heart, gut and central nervous system.