Novel rhodanine-based amide derivatives were prepared in good yields via Passerini reaction of rhodanine-N-acetic acid with aromatic aldehydes and tert-butyl isocyanide in the presence of tetramethylguanidine immobilized on silica nanoparticles (TMG-SiO2 NPs) as a heterogeneous base catalyst. The synthesized compounds were evaluated for their antibacterial effects against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis.