The synthesis and spectral analysis of some new 1,3-dihydro-3-hydroxy-3-[2-hydroxyimino-2-(substituted phenyl)ethyll-2H-indol-2-ones (21-32) and spiro[3H-indol-3,5'-(4'H)-isoxazol]-2(1 H)-ones (33-44) are described. Sixteen of the synthesized compounds were screened in vitro for their growth inhibitory activity against thirteen species of microorganisms, viz, S. aureus, S. epidermidis, S. faecalis, B. subtilis, B. cereus, E. aerogens, E. coli, P. aeruginosa, P. vulgaris, A. baumonia, A. faecalis, C. albicans and S. cervicae. Most of the compounds exhibited significant antimicrobial activity especially the oximes 28 and 29.