This work describes the facile microwave synthesis of interlayer expanded, nanosized MoS2 sheets that are vertically aligned on a well-conducting reduced graphene (rGO) support, as confirmed by X-ray diffraction, Raman and X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive X-ray analysis, and high-resolution transmission electron microscopy. Such structure has been predicted to be highly favorable for efficient electrocatalysis of hydrogen evolution by MoS2 but could not be achieved until now. Films deposited from the microwave-synthesized MoS2-rGO composites demonstrate outstanding and stable hydrogen evolution performance in acidic solution. These catalysts exhibit an exchange current density as high as 1.0 ± 0.2 A g-1 MoS2-rGO, sustain a current density of 10 mA cm-2 (36 A g-1 MoS2-rGO) at an overvoltage of 0.104 ± 0.002 V, and maintain steady performance for many hours. Importantly, our simple synthesis affords several advantages over more sophisticated methods used previously to prepare MoS2 catalysts.