Lymphoid organs such as thymus and lymph node develop from anlagen during embryonic development. This process is known to rely and chemokine producing stroma cells as well as lymphoid tissue inducers (LTI) cells expressing the chemokine receptors. In addition to those secondary lymphoid organs it is well known that lymphoid structures can be induced even in adults as a consequence of chronic inflammatory insults. Currently little is known about the molecular mechanisms that control the development, maintenance and organization of these tertiary lymphoid organs. In this presentation, I will summaries present knowledge on the role of the chemokine system during lymphoid organ development and will present new data on the role of chemokine-driven homing of regulatory T cells in controlling the development of tertiary lymphoid organs.