A new species of primitive tuskless burrowing mayflies (Ephemeroptera: Palpotarsa: Behningiidae), Behningia baei, new species, is described from larvae taken in Thailand. The new species is differentiated from congeners primarily by its labial palps, labrum, and base of the mid legs. It is the first species of the genus Behningia, and only the second species of the family Behningiidae, to be taken from the Oriental biogeographic region. Larvae previously regarded as B. tshernovae Edmunds and Traver are considered to be assignable to B. lestagei Motas and Bacesco.