Microtubules are among the main constituents of the cytoskeleton. They are assembled from dimers of alpha- and beta-tubulin. This assembly occurs preferentially at organizing centers such as the centrosomes, catalyzed by multiprotein complexes of gamma-tubulin. At the beginning of mitosis, the amount of gamma-tubulin complexes at the centrosomes increases sharply, supporting the sudden formation of numerous spindle microtubules. Recent studies on the structure of gamma-tubulin complex proteins have advanced our understanding of the assembly process of gamma-tubulin complexes, and have pointed toward putative mechanisms of microtubule nucleation. Moreover, the discovery of novel proteins associated with gamma-tubulin complexes has illustrated the possibilities of how gamma-tubulin might be recruited and regulated at specific sites of microtubule organization. This chapter highlights recent developments in the field and discusses the potential of the gamma-tubulin complex as a pharmacological target, to control proliferation of cells.