During Drosophila neuroblast lineage development, temporally ordered transitions in neuroblast gene expression have been shown to accompany the changing repertoire of functionally diverse cells generated by neuroblasts. To broaden our understanding of the biological significance of these ordered transitions in neuroblast gene expression and the events that regulate them, additional genes have been sought that participate in the timing and execution of these temporally controlled events. To identify dynamically expressed neural precursor genes, we have performed a differential cDNA hybridization screen on a stage specific embryonic head cDNA library, followed by whole-mount embryo in situ hybridizations. Described here are the embryonic expression profiles of 57 developmentally regulated neural precursor genes. Information about 2389 additional genes identified in this screen, including 1614 uncharacterized genes, is available on-line at 'BrainGenes: a search for Drosophila neural precursor genes' (http://sdb.bio.purdue.edu/fly/brain/ahome.htm).