This work focuses on the structural aspects of the region of São Francisco de Assis, in the State of Rio Grande do Sul. The presence of the Itu Dome (6) was not confirmed, and a main anticline was associated with a syncline and another parallel anticline, with very gentle slopes, to the northwest. Structural features were formed not only by layer diving, but also by blocks of faults. Dams and sills of diabase were intruded along the main lines of weakness. The age of the Cretaceous structures and they are related to the arching of the Shield Sul-rio-Grandense.