In this article, a boiling model for "Fluent 6" fluid flow simulation software, for its use in gas-liquid heat exchangers, is presented. After a thorough study of existing bibliographies, a physical model has been compiled, which has been incorporated into the eulerian multiphase model, the most suitable of those available in Fluent for the resolution of these kinds of multiphase flows. Also discussed are some of the aspects of the implementation, which basically consist of the modeling of the interactions between phases as source terms in the governing equations solved by Fluent. Finally, the implementation of the model has been validated against experimental tests from the available literature, achieving a satisfactory degree of concordance.