The title compound, 3-amino-5-methyl-5-(4-pyrid-yl)imid-azol-idine-2,4-dione, C(9)H(10)N(4)O(2), was obtained by reaction of 5-methyl-5-(4-pyrid-yl)hydantoin with hydrazine. It crystallizes as a racemate in the tetra-gonal space group I4(1)/a with one mol-ecule in the asymmetric unit. The dihedral angle between the pyridine ring and the five-membered hydantoin ring is 47.99 (3)° In the crystal structure, mol-ecules are joined in a three-dimensional hydrogen-bonded network by N-H⋯N and N-H⋯O links.