Fil: Agüero, Alexis. Departamento de Geología y Petróleo, Universidad Nacional del Comahue; Argentina.Fil: González, Pablo Diego. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina.Fil: De la Puente, Susana. IITCI-CONICET; Argentina.The aim of this contribution is to describe the metamorphic and structural evolution of the basement rocks of the Chacay stream, at the northern portion of the Cordillera del Viento, Neuquén. The rocks are affected by an M1 regional metamorphism under greenschist facies and F1 decametric folds with western tectonic transport. Then, the already deformed and regionally metamorphosed rocks are intruded by two granitoid plutons and affected by local contact metamorphism. As a thermal effect of contact metamorphism, hornfels and migmatite were formed. Finally, the entire basement is affected by high-angle reverse faults that also have western tectonic transport.