New 2(1H)-quinoxalinones and their hexahydro derivatives were prepared for investigating their antimicrobial and antiinflammatory activities. The study showed that thiosemicarbazide 6a derived from the hexahydro-2(1H)-quinoxalinone series has nearly the same antibacterial activity as the reference drug ciprofloxacin. Moreover, the 2(1H)-quinoxalinones bearing N-phenyltriazole (9a) or 4-chlorophenyl-2,3-dihydrothiazole (13b) moieties were the most active ones after 4 h with use of the rat hind paw edema method, whereas their antiinflammatory and ulcerogenic activities were comparable with the selective COX-2 inhibitor celecoxib.