A new species of termite, Orthognathotermes heberi, is described and the soldiers illustrated. It is similar in morphology and the structure of its nests to O. gibberorum from Mato Grosso. The soldiers are strongly dimorphic, 14% being minor soldiers whose heads are only 59% the length of those of the major ones. No such dimorphism has been recorded in any of the seven species already known in the genus.