Some novel 2,4-diaryl-3-azabicyclo[3.3.1] nonan-9,50 -spiro-10 ,20 ,40 -triazolidine-30 -thiones 22–28 were synthesized and studied for their in vitro antibacterial and antifungal activities. Compounds 23, 24 and 26 exhibit potent antibacterial activity against tested S. aureus. Compounds 24 and 26 possess good activity against K. pneumoniae. Compound 24 is active against S. typhii and E. coli, whereas compounds 25 and 26 show excellent antibacterial activity against b-H. streptococcus. Compounds 23–26 with electron withdrawing functional groups at the para position of the phenyl rings at positions 2 and 4 of the bicyclic ring shows excellent antifungal activity against all the tested fungal strains.