During field studies in River Mincio, northern Italy, populations of the aquatic megadrile Sparganophilus tamesis Benham, 1892 were discovered, the worms being particularly abundant among the roots of Vallisneria spiralis L. This finding represents the first record of Sparganophilidae in Italy. A morphological account, with photographs of worms and cocoons, as well as field and laboratory remarks on density, behaviour and habitat, are provided. The view of S. tamesis being senior synonym to S. eiseni Smith, 1895 is favoured, as is the hypothesis of the arrival and spreading of Sparganophilus in Europe amongst the roots of water plants.