Leptodactylus latinasusJiménez de la Espada, 1875 at Punta Lara, Province of Buenos Aires, Argentina, was assigned to cohorts on the basis of snout‐vent length, development, and reproductive condition. Frogs were sampled by pitfall traps during December 1985 to November 1986. Two age‐classes were observed during this period. Bertalanffy's model was applied for the study of growth, which showed an effective fitness to the data obtained from the samples.