Hydrangea-like silver bromide/zinc oxide (AgBr/ZnO) photocatalysts were first synthesized using a one-pot, wet chemical method, and were composed of a ZnO hierarchical structure and AgBr nanoparticles (NPs). The as-synthesized AgBr/ZnO composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS) mapping analysis. The experimental results suggested that the AgBr NPs were uniformly decorated on the surface of the self-assembled ZnO hierarchical structure. It was found that poly vinyl pyrrolidone (PVP) and triethanolamine (TEOA) played important roles in the formation of the AgBr/ZnO hydrangea-like structure. The photocatalytic performance of AgBr/ZnO composites was then investigated using the degradation of rhodamine B under visible light irradiation. AgBr/ZnO composites exhibited better photocatalytic properties than pristine ZnO and AgBr, and the composite with 30% AgBr showed the best photocatalytic activity. The enhanced catalytic properties were attributed to the synergistic effects of the hierarchical hydrangea like structures, AgBr/ZnO heterojunction and metallic silver generated during the photocatalytic process. Therefore, the hydrangea-like AgBr/ZnO could act as a potential photocatalyst for environmental treatment and energy conversion.