Molybdenum diarsenide is an arsenide of molybdenum, with the chemical formula MoAs<sub>2</sub>. Other arsenides of molybdenum are Mo<sub>2</sub>As<sub>3</sub> and Mo<sub>5</sub>As<sub>4</sub>.
Molybdenum diarsenide can be prepared by the reaction of molybdenum and arsenic at 570 ðC.
Molybdenum diarsenide is a black solid, and is a superconductor at 0.41 K. It crystallises in the monoclinic crystal system, with space group (No. 12). It has the same structure as molybdenum diphosphide. It is insoluble in concentrated hydrochloric acid or hydrogen peroxide, but easily soluble in nitric acid, hot concentrated sulfuric acid and aqua regia.