The construction of heterostructures is regarded as an excellent strategy to achieve efficient charge separation and improved photocatalytic activity. Herein, a series of Bi2MoO6/ZnO hierarchical heterostructured photo catalysts were synthesized by a solvothermal method. The morphology of Bi2MoO6 grown on the surface of ZnO nanorods could be controlled by adjusting the experimental conditions. The synthesized samples were characterized by various analytical techniques and their photocatalytic performance was evaluated by photocatalytic reduction of Cr(VI) under visible-light irradiation. Compared with those of pure Bi2MoO6 and ZnO, the Bi2MoO6/ZnO composites showed higher photocatalytic activity towards the reduction of Cr(VI). The enhanced photocatalytic activity was mainly attributed to the formation of a heterojunction between Bi2MoO6 and ZnO, which effectively facilitated the separation and transfer of electrons and holes. In addition, the Bi2MoO6/ZnO photocatalysts maintained good stability after three cycles of Cr(VI) photoreduction. A possible photocatalytic mechanism of the as-synthesized composites was proposed.