In the present study, 20 new compounds having 3-[2-(5-aryl-1,3,4-oxadiazol-2-yl] imino-4-thiazolidinon-5-ylidene]-5-substituted/nonsubstituted 1H-indole-2-one (I-XII) and 3-[2-(4-carbetboxymethylthiazol-2-yl)imino-4-thiazolidinon-5- ylidene] -5-substituted/nonsubstituted 1H-indole-2-one (XIII-W systems were synthesized. The structures were confirmed by spectral methods (UV, IR, H-1-NMR, C-13-NMR, C-13-DEPT (135), electron impact mass spectrometry) and elemental analysis. All compounds were tested for in vitro antimicrobial activity against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis ATCC 14153, Candida albicans ATCC 10231, Microsporum gypseum (NCPF-580), Microsporum canis, Trichophyton mentagrophytes and Trichophyton rubrum and some of them were found to be active. Especially, compound I was more active than cefuroxime sodium (CAS 56238-63-2) which was used as a standard, and the activity of compound XII was close to that of cefuroxime sodium against Staphylococcus epidermidis ATCC 12228. Primary screening for antituberculous activity was conducted at 6.25 mu g/ml against Mycobacterium tuberculosis H37Rv in BACTEC 12B medium using the BACTEC 460 radiometric system. The anticonvulsant activities of selected prototoype compounds (I, IV-VI, VIII, XI, XIII, XVI-XVIII) administered at doses of 50-200 mg/kg (i.p.) were evaluated using the pentetrazol test (PTZ) in mice.