Two complexes [Cd(L)(CH₃O)(CH₃COO)]·CH₃OH·(CH₃)₂NH (C1) and [Mn(L)Cl₂(CH₃OH)] (C2) were synthesized by reacting a new imidazole-bearing ligand 4-(1H-imidazol-1-yl)-N′-(pyridin-2-ylmethylene)benzohydrazide (L) with cadmium and manganese salts, respectively. The ligand was characterized by ¹H NMR and ¹³C NMR spectroscopy, while the complexes were analyzed by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analyses, and UV-Vis spectroscopy. Complex C1 features a 1D zigzag chain structure formed by alternating connections of one ligand and one metal ion. In contrast, complex C2 exhibits a mononuclear molecular structure, where each unit consists of one ligand connected to one manganese ion. Both complexes further form a 3D structure through π-π interactions and intermolecular hydrogen bonds. Cell proliferation assays conducted on four tumor cell lines and one normal cell line revealed that both C1 and C2 exhibited significantly stronger inhibition of tumor cell growth compared to the ligand L. Notably, C1 demonstrated superior anti-proliferative activity against A549 and A2780 cells relative to cisplatin, while showing comparable cytotoxicity toward SMMC-7721 cells. Further mechanistic studies indicated that C1 induces apoptosis in both SMMC-7721 and A549 tumor cells, suppresses the invasion and migration of SMMC-7721 cells, and arrests the cell cycle at the G0/G1 phase.