Androlaelaps maurii , a new species of laelapine mite, is described on the basis of female specimens collected from the pelage of the akodontine rodent, Deltamys kempi, from La Plata River basin in Argentina. Androlaelaps maurii can be differentiated from closely related species by its smaller size, the differing distribution of setae in the dorsal shield, and an unarmed opithogaster. This mite appears to be host specific to D. kempi and occurs on this rodent throughout its distribution in Argentina and Uruguay.