Rhotekin is an effector protein for small GTPase Rho. This protein consists of a Rho binding domain (RBD), a pleckstrin homology (PH) domain, proline-rich regions and a C-terminal PDZ-binding motif. We and other groups have identified various binding partners for Rhotekin and proposed their possible physiological roles. However, functions of Rhotekin per se are largely unknown and information about its physiological roles are fragmentary. In this review, we summarize known features of Rhotekin in neuronal tissues and cancer cells. We also describe characteristics of binding partners for Rhotekin and predicted roles of their interaction.