In this study, an efficient synthesis and the antimicrobial activity evaluation of some 4‐oxo‐thiazolidin‐2‐ylidene derivatives are presented. The structures of the target substances were confirmed by using 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, infrared spectroscopy, and elemental analysis. The synthesized compounds were evaluated for antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). It was shown that the compounds in this series possess antibacterial and antifungal activities.