The pulmonate land snail, Rumina decollata, is a highly invasive gastropod adapted to arid conditions, and native from the Mediterranean area. It was recorded for the first time in Argentina in 1988, in the northeastern Pampas of the Buenos Aires Province, a region characterized by a humid mesothermal climate with no water deficit. In the present contribution, we report the finding of populations of this species in the semiarid region of La Pampa and Mendoza provinces in central-western Argentina. The present findings extend the invasive distributional range of R. decollata westwards through more than 1000 km from the site where it was detected in 1988. Although no damages to agricultural areas have been reported to the moment in Argentina, the presence of R. decollata in semiarid areas warns us about its potential as an important plague in the future.