The response of an Araucaria araucana forest, located at Cunco County, Ninth Region of Chile, was studied by applying a method that determines the cut allowable through the marginal analysis of volume and diameter class movement, with the aim of regulating forest. Following the method, a minimum diameter for harvesting of 110 cm and a harvest cycle of 37 years was established as suitable for ensuring the resource sustainability, preserving the forest capital, and keeping the structure and floral composition unchanged. Mediation may be considered using selective, sanitary, and silvicultural harvesting.