Molecules of the title compound [systematic name: (5-amino-3-methylpyrazol-1-yl)(phenyl)methanone], C(11)H(11)N(3)O, contain an intramolecular hydrogen bond. The molecules are linked into sheets by a combination of N-H...N, C-H...O and C-H...pi(arene) hydrogen bonds. Comparisons are made with the hydrogen-bonded structures of some related compounds.