The subterranean freshwater species Niphargus wolfi Schellenberg, 1933 (Amphipoda: Gammaridea, fam. Niphargidae) is discovered in Italy in numerous localities, sometimes associated with other Niphargus species. N. wolfi is redescribed and figured for the first time based on specimens from Italy, and its variability and taxonomical position within the genus Niphargus Schiödte, 1849, are discussed.