The objective was to evaluate the economic efficiency of two groups of cows in a grazing system using a non-traditional estimation strategy. Retrospective data were used corresponding to the lactations of 216 primiparous and multiparous cows of Holstein breed American-Canadian biotype with records of all their productive life, from their incorporation to the system until their sale or death, collected between the years 1992-2012. It was concluded that the economic efficiency of the two groups of cows analyzed is not only determined by milk production, but by a set of additional variables such as longevity and reproduction.