5-Phenyl-1,3,4-oxadiazole-2(3 H )-thione

In the title compound, C8H6N2OS, the planar oxadiazole ring is effectively coplanar with the phenyl ring. This facilitates the formation of N—H⋯S inter­actions, leading to a thione tautomer in the solid state, and the formation of centrosymmetric dimers.