Thousands of genes show differential expression patterns during kidney development, suggesting that the genetic program driving this process is complex. While great progress has been made in defining the outline of the genetic basis of nephrogenesis, it is clear that much remains to be learned. A global atlas of the gene expression profiles of the multiple elements of the developing kidney would allow the identification of novel growth factor-receptor interactions, identify additional molecular markers of distinct components, facilitate the generation of compartment specific GFP-CRE transgenic mouse tools, lend insights into the genetic regulatory circuits governing nephron formation, and fully characterize the waves of gene expression that impel nephrogenesis. Both microarrays and next generation deep sequencing of cDNA libraries can be used to define comprehensive, sensitive, and quantitative gene expression profiles. In addition, laser capture microdissection and transgenic GFP mice can be used to isolate specific compartments and pure cell types from the developing kidney. Advancing technologies are even allowing robust gene expression profiling of single cells. The final goal is the production of an exquisitely detailed atlas of the gene expression program that drives kidney development.