El Toro underground mine is located at Antioquia, Colombia and exploits a limestone deposit through sublevel stopping mining method. The mine was designed with five exploitation levels with 65m high, 20m wide and 120 m long stopes sets. In this work is presented the process to obtain the assessment of the mechanical behavior of the rock mass under stoping effects, the geomechanical and numerical models were obtained and several stopes configurations were evaluated including existing and projected openings. The work concludes with geometrical modification that besides to offer stability of ground, allows to extract greater volume of mineral reserves.