The title compound, {[Li(C5H3N2O2)(H2O)]·0.5H2O}n, comprises four symmetry-independent Li(C5H3N2O2)(H2O) units which form molecular ribbons running along the c-axis direction. Within each ribbon, the ligand molecule, acting in a μ2-mode, bridges two adjacent Li+ cations using both of its N,O-bonding sites. The coordination environment of each of the four Li+ cations can be described alternatively as either slightly distorted trigonal–bipyramidal or slightly distorted square–pyramidal. The ribbons are interconnected by a network of O—H...O hydrogen bonds.