In the title compound {systematic name: 4,4'-[1,1'-(hydrazinediyl-idene)bis-(ethan-1-yl-1-yl-idene)]bis-(benzene-1,3-diol)}, C16H16N2O4·2C3H7NO, the (E,E)-2',4'-di-hydroxy-aceto-phenone azine mol-ecule is centrosymmetric, the mid-point of the N-N bond being located on an inversion centre. All the non-H atoms of the azine mol-ecule are approximately coplanar, the maximum deviation being 0.017 (2) Å. An intra-molecular O-H⋯N hydrogen bond occurs between the azine N atom and the hy-droxy group. In the crystal, azine and di-methyl-formamide solvent mol-ecules are linked by O-H⋯O hydrogen bonds.