Quetrupillán lies on the border between the Los Rios Region and the La Araucanía Region, in the Southern Volcanic Zone. Together with Villarrica and Lanín it forms a northwest-southeast alignment of volcanoes, which may be a transcurrent fault. The Cordillera El Mocho and Quinquilil volcanoes are likewise situated on this alignment, both are deeply eroded composite volcanoes of small dimensions. Other volcanoes in the Southern Volcanic Zone have similar alignments, such as Nevados de Chillán and Puyehue-Cordon Caulle. In comparison to Villarrica, Quetrupillán has been less active and its eruptions were also smaller than Villarrica's, with no large pyroclastic flows found at Quetrupillán.