Gammarus gauthieri (Karaman) was known from North Africa only. During systematic sampling, carried out in 1969 to 1970, it became clear, that the species is also widely distributed in the Iberian peninsula. Comparative descriptions of this species and of two other members of the Gammarus pulex-group, G. ibericus Margalef (new rank) from Spain, and G. acalceolatus nov. spec. from Morocco, are given.