The type III secretion needle complex (NC) of Salmonella typhimurium is a complex secretory system that functions to translocate virulence proteins into eukaryotic cells. Evolutionarily it is related to bacterial flagella. Assembly of the NC occurs through ordered secretion, polymerization, and assembly, and requires the coordinated expression and association of over 20 different proteins. Recent progress in the understanding of the assembly and architecture of the NC is reviewed.