A series of 22 synthetic drug-like hydantoin derivatives, including aryl or alkenyl 5,5-disubstituted hydantoins, spirohydantoins and annulated bicyclic and tricyclic hydantoins, was assayed for in vitro antibacterial and antifungal activity. The antimicrobial activity was tested by determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) using microdilution method. The tested hydantoin derivatives showed moderate antibacterial and weak antifungal activity. The intensity of acting varied depending on the structure and concentration of the test substances and the type of test organisms. The bicyclic benzeneselenenyl derivatives of hydantoin have shown the highest inhibitory activity. The tested compounds appeared as promising for a fragment-based drug design approach and further bioactivity studies.