Achieving control over the morphology of zeolite crystals at the nanoscale is crucial for enhancing their performance in diverse applications including catalysis, sensors and separation. The complexity and sensitivity of zeolite synthesis processes, however, often make such control both highly empirical and difficult to implement. We demonstrate that graphene can significantly alter the morphology of titanium silicalite (TS-1) particles, in particular being able to reduce their dimensions from several hundreds to less than 10 nm. Through electron microscopy and molecular mechanics simulations we propose a mechanism for this change based on the preferential interaction of specific TS-1 surfaces with benzyl-alcohol-mediated graphene. These findings suggest a facile new means of controlling the zeolite morphology and thereby also further demonstrate the potential of graphene in hybrid materials. Moreover, the generality of the mechanism points the way to a new avenue of research in using two-dimensional materials to engineer functional inorganic crystals.