In the title trinuclear NiII compound, [Ni3(C18H19N2O3)2(C5H5N)4]·C3H7NO·H2O, three NiII cations are bridged by two N′-(adamantan-1-ylcarbonyl)-2-oxidobenzohydrazidate trianions. The central NiII cation has a distorted octahedral N4O2 coordination environment where a reverse torsion occurs between the two bridging ligands, whereas the two NiII cations on the sides each adopt an N2O2 square-planar coordination. Weak intramolecular C—H⋯O and C—H⋯N interactions help to stabilize the molecular structure. In the crystal, the lattice water molecule links with the NiII complex and dimethylformamide solvent molecule via O—H⋯O hydrogen bonding.