A survey of the current treatment of the allochthonous grass Digitaria ciliaris and of its actual distribution in Europe is offered. It is based on a comprehensive revision of vouchers from selected European herbaria and on a literature survey carried out with the goal of collecting additional reports and of reviewing the treatment of the species in national and regional European floras. The results suggest that D. ciliaris is still not well known in Europe and thus overlooked in many areas, particularly in Italy and Spain. First records or at least definitely confirmed records are given for Portugal, Montenegro and Turkey, as well as for several regions of Spain, Italy and Greece. Substantial evidence is provided that D. ciliaris is naturalized in large areas of S Europe, particularly along the Mediterranean coasts of the Iberian Peninsula, Italy and Greece, including the islands. Diagnostic morphological features of D. ciliaris are described in order to better understand the species and an elaborated key is provided to distinguish it from the very similar and common autochthonous D. sanguinalis and other allochthonous species of the D. ciliaris complex that occur or may occur in Europe as casuals.