Rab11a is a small GTP binding protein enriched in the pericentriolar plasma membrane recycling systems. We hypothesized that Rab11a binding proteins exist as downstream effectors of its action. Here we define a family of four Rab11 interacting proteins: Rab11-Family Interacting Protein 1 (Rab11-FIP1), Rab11-Family Interacting Protein 2 (Rab11-FIP2), Rab11-Family Interacting Protein 3 (Rab11-FIP3) and pp75/Rip11. All four interacting proteins associated with wild type Rab11a and dominant active Rab11a (Rab11aS20V) as well as Rab11b and Rab25. Rab11-FIP2 also interacted with dominant negative Rab11a (Rab11aS25N) and the tail of Myosin Vb. The binding of Rab11-FIP1, Rab11-FIP2 and Rab11-FIP3 to Rab11a was dependent upon a conserved carboxyl-terminal amphipathic a-helix. Rab11-FIP1, Rab11-FIP2 and pp75/Rip11 colocalized with Rab11a in plasma membrane recycling systems in both non-polarized HeLa cells and polarized MDCK cells. GFP-Rab11-FIP3 also colocalized with Rab11a in HeLa cells. Rab11-FIP1, Rab11-FIP2 and pp75/Rip11 also co-enriched with Rab11a and H+K+-ATPase on parietal cell tubulovesicles, and Rab11-FIP1 and Rab11-FIP2 translocated with Rab11a and the H+K+-ATPase upon stimulating parietal cells with histamine. The results suggest that the function of Rab11a in plasma membrane recycling systems is dependent upon a compendium of protein effectors.