FSM-16-SO₃H nanoparticles were prepared using a sol-gel method at room temperature. The prepared FSM-16-SO₃H was used to catalyze the synthesis of polyhydroquinolines through a one-pot, four-component reaction of aldehydes, dimedone, ethyl cyanoacetate, and ammonium acetate under reflux condition in EtOH as a green solvent. To investigate the textural properties of the prepared catalyst, various techniques were applied such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, and Brunauer–Emmett–Teller. High catalytic activity, easy handling, and thermal stability are the superior properties that could be denoted after successive investigations of this catalyst. In addition, the catalyst can be recovered easily and reused effectively for several cycles.