Pyridine-4-carboxylic acid (PYCA) functionalized Fe3O4 nanoparticles as an organic–inorganic hybrid heterogeneous catalyst was fabricated and characterized by FT-IR, XRD, TGA, TEM, SEM, and VSM techniques. The catalytic activity of the magnetic catalyst was probed through one-pot synthesis of pyrano[3,2-b]pyranone derivatives from three component reactions of aromatic aldehydes, kojic acid, and ethyl cyanoacetate under solvent-free conditions. Some advantages of this protocol are its environmentally benign method, simple procedure, high yields, and short reaction time. The catalyst was readily separated using an external magnet and reusable without significant loss of its catalytic efficiency.