H2O-mediated efficient, tandem synthesis of barbituryl thiocarbamides by the nucleophilic addition reaction of uramil and aryl isothiocyanates using Amberlyst-15 as a heterogeneous solid catalyst is being reported. The novel and clean methodology offers the advantages that includes short reaction time, good yields, and operational simplicity, less leaks, environmentally benign procedure apart from recyclable, reusable catalyst. Keywords; Thiocarbamides, green synthesis, Amberlyst-15.