This is an updated second edition of "Acridomorph (Orthoptera) species of Argentina and Uruguay" (2006). The original checklist was compiled by C. S. Carbonell from information that he obtained throughout his scientific carreer. Names of genera, species, and subspecies have been listed. For each species, the following information is given: synonyms, geographic distribution, main host plants, economic importance according to the categories defined in "The Locust and Grasshopper Agricultural Manual" (COPR, 1982), some selected observations, and the most relevant bibliographical references. The species are illustrated with photographs of male and female individuals, and the habitat, when they have been taken in nature. The information on the geographical distribution of the species was obtained by the authors through their own field work and from the available scientific literature.