The State of Chiapas has a wide array of cultivated mangoes which could potentially be important for plant breeding of this species. Phenotypic characteristics of fruits and trees are useful indicators in differentiating Chiapas landrace mangoes from commercial ones, but they are not precise. In this study we determined the isoenzymatic diversity of 16 collections of mango landraces and five commercial varieties grown in the Soconusco Region, Chiapas, Mexico, using seven isoenzymatic systems. The analyzed mango landraces have the following common names: Coche, Piña, Madura verde, Canela, Amate, Tecolote, Oro, Tapanero, Manilón, Alcanfor, Manzana, Manililla, Blanco, Melocotón, Amatillo, and Pomarrosa; the improved varieties were Ataulfo (50 to 70 year old), Tommy, Atkins, Kent and Manila. Twenty polymorphic markers were located, but none of the enzymatic systems, by itself, allowed differentiation of each of the mangoes studied; however, combination of the enzymatic systems GPI-1 and GPI-2, generated unique patterns that allowed characterization of the different mangoes. The dendrogram suggested the presence of 83 % of similarity among the analyzed varieties, resulting in three groups: one group included Pomarrosa mango, which was clearly different from the others. A second group included landraces with similar fruit characteristics, with a high amount of fiber and sugar and without commercialization traits. The third group included commercial mangoes and some landraces that are commercialized locally that share similarities for some fruit traits, such as the absence of fiber in the pulp and high sugar content.