In this revision of the Patagonian predaceous midges of <i>Stilobezzia (Acanthohelea)</i> (Diptera: Ceratopogonidae), the seven previously known species, <i>Stilobezzia bicinctipes</i> Ingram and Macfie, <i>S. hirsuta</i> I. and M, <i>S. ornaticrus</i> I. and M, <i>S. patagonica</i> I. and M, <i>S. rava</i> I. and M, <i>S. succinea</i> I. and M. and <i>S. varia</i> I. and M. are redescribed, illustrated and their distributions are expanded. Diagnoses are provided for <i>Stilobezzia curvistyla</i> Cazorla and Spinelli, <i>S. longisternalis</i> Cazorla and Spinelli and <i>S. nigerrima</i> I. and M, and the male of <i>S. bicinctipes</i> and the female of <i>S. ornaticrus</i> are described for the first time. Seven new species are described with photographs: <i>S. estepae</i>, <i>S. mapuche</i>, <i>S. megatheca</i>, <i>S. monomorphica</i>, <i>S. pabloi</i>, <i>S. spinosa</i> and <i>S. tridentis</i>. The species are illustrated by photographs, and a key to males and females is provided as well as distributional maps for all species.Facultad de Ciencias Naturales y Museo