A magnetically supported ionic liquid on Fe 3 O 4 @SiO 2 nanoparticles (MNPs@ SiO 2 -IL) was synthesized and evaluated as a recoverable catalyst for the one-pot synthesis of 1,3-thiazolidin-4-ones in high to excellent yield under solvent-free conditions. The MNPs@SiO 2 -IL catalyst was characterized via Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Moreover, the catalyst could be easily recovered by magnetic separation and recycled for 10 times without significant loss of its catalytic activity.