Root development of Arabidopsis, Zea mays (maize) and Oryza sativa (rice) differs in both overall architecture and the anatomy of individual roots. In maize and rice, the post-embryonic shoot-borne root system becomes the major backbone of the root stock; in Arabidopsis, the embryonic root system formed by a simple primary root and its lateral roots remains dominant. Recently, several specific root mutants and root-specific genes have been identified and characterized in maize and rice. Interestingly, some of these mutants indicate that the formation of primary-, seminal-, crown- and lateral roots is regulated by alternative root-type-specific pathways. Further analyses of these unique pathways will contribute to the understanding of the complex molecular networks involved in cereal root formation.