Epithelial cells of the kidney proximal tubules, which reabsorb water and nutrients from the forming urine, shrink in response to fluid flow through mechanisms that involve mechanosensing by primary cilia. Orhon et al. demonstrated that the application of fluid flow induced autophagy in cultured mammalian kidney epithelial cells. This autophagic response to flow depended on the presence of functional cilia and was necessary for cell shrinkage. Similarly, inhibition of autophagy or interference with cilia formation increased the size of epithelial cells in mouse kidneys in vivo. Together, this study shows that autophagy can be induced by mechanical signals transduced by primary cilia and can function in regulating cell volume. It would be interesting to uncover the precise mechanisms of autophagy-mediated cell volume regulation.