Uracil, the pyrimidine nucleobase, which combined with adenine forms one of the major motifs present in the biopolymer RNA, is also involved in the self-assembly of RNA. In the title compound, C(9)H(14)N(4)O(2)·2H(2)O, the asymmetric unit contains one dimethyl-amino-uracil group and two water mol-ecules. The plane of the N=C-NMe(2) side chain is inclined at 27.6 (5)° to the plane of the uracil ring. Both water mol-ecules form O-H⋯O hydrogen bonds with the carbonyl O atoms of the uracil group. Additional water-water hydrogen-bond inter-actions are also observed in the crystal structure. The O-H⋯O hydrogen bonds lead to the formation of a two-dimensional hydrogen-bonded network cage consisting of two dimethyl-amino-uracil groups and six water mol-ecules.