A new species of the Andean stag beetle genus Auxicerus Waterhouse, 1883 is described from the humid Tucuman-Bolivian forest in the southern Bolivian Andes. Auxicerus magnipunctatus sp. nov. is distinguished from all congeners by the distinctly larger punctures of the mesosternum; antennomeres 2–6 subquadrate, last two joints of club wider than long; lamellae not widely separated; posterior end of ocular canthus rounded and anterior edge of canthus moderately developed into an obtuse triangle. Auxicerus magnipunctatus sp. nov. is possibly endemic to the Tucuman-Bolivian forest. Along with the presence of other endemic beetle species with tropical congeners, the discovery of A. magnipunctatus sp. nov. supports the idea that the persistence of rather tropical taxa in the subtropical realm is fostered by increased humidity at orographic rain barriers and climatic stability in the Tucuman-Bolivian forest.