Novel p-nitrophenyl maleanilic acid bidentate free ligand (PNMA) was synthesized eco-friendly by solvent free reaction between 4-nitroaniline and maleic anhydride. Some novel mixed ligand organometallic chelates of formulae [M(CO)4L] (M = Cr , Mo , or W and L = PNMA) were carefully prepared under nitrogen inert gas atmosphere by condensation between ligand PNMA and hexacarbonyl of metal cations Cr , Mo , or W in 1:1 molar ratio. The chemical structures of PNMA free ligand and its novel chelates had been evaluated by elemental analyses, FTIR spectroscopy, 1H-NMR, mass spectroscopy, and thermal analyses (TGA and DTG). The chemical structures of both PNMA free ligand and its chelates were investigated also by XRD technique. The free ligand and its chromium chelate had been evaluated for their anticancer activities against MCF‐7 cells (breast cancer cell line), HCT116 cells (colon cancer cell line) and HepG2 cells (human liver cancer cell line).