p-Toluic hydrazide was used for synthetizing a new Schiff base <I>N</I>'-(2,3-dihydroxybenzylidene)-4-methylbenzohydrazide (I). The prepared compound was characterized by elemental analysis, infrared and <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy techniques, and the structure of compound (I) was determined by single-crystal X-ray diffraction study. The compound (C<sub>15</sub>H<sub>14</sub>N<sub>2</sub>O<sub>3</sub>) crystallises in the monoclinic space group <I>P</I>2<sub>1</sub>/<i>n</i> with the following unit cell parameters: <i>a</i> = 11.7820 (6) Å, <i>b</i> = 8.5278 (4) Å, <i>c</i> = 13.6054 (7) Å, <i>β</i> = 109.346 (5)°, <I>V </I>= 1289.81 (12) Å<sup>3</sup>, <I>Z</I> = 4, <I>R</I><sub>1</sub> = 0.071 and <i>wR</i><sub>2</sub> = 0.197. The X-ray structure shows that the compound (I) adopts an <I>E</I> configuration with respect to the double bond C7=N1. The carbonyl oxygen atom O3 and the nitrogen atom N1 of the hydrazide moiety are in a <i>syn</i> conformation with respect to C8—N2 bond. The crystal packing of compound (I) is stabilized by intramolecular O(phenol)–H•••N(carbohydrazide) which results in an <I>S</I>(6) ring motif and intermolecular O(phenol)–H•••O(carbohydrazide) hydrogen bonds which form chains. The carbonohydrazide moiety C=N–N–C(O)–N–N=C fragment is almost coplanar with the two benzene rings with dihedral angles of their mean planes of 10.35° [C1—C6] and 7.99° [C9—C14], respectively. The dihedral angle between the mean planes of the phenyl rings is 2.46°.