Arrestins were originally identified as negative regulators of G protein-coupled receptor signaling. Recently, their diverse functions in intracellular signaling pathways as scaffold and signaling intermediate emerged providing mechanisms for achieving signal specificity and to attack for pharmacological intervention. Here, we summarize the importance of beta-arrestin function for WNT/Frizzled (FZD) signaling. WNTs are secreted lipoglycoproteins acting through the seven transmembrane spanning receptors of the FZD family. During the last years it became evident that beta-arrestins are required for cellular communication by means of WNTs and FZDs both in cellular systems as well as in vivo. Although the overall importance of arrestin for WNT/FZD signaling remains still obscure, interaction with the central phosphoprotein disheveled and the endocytic machinery implicate beta-arrestin as a determinator of WNT signaling specificity, mediator of WNT/FZD desensitization and regulator of signaling compartmentation.