A new class of isoxazole derivatives containing 1,2,4-triazole moiety was synthesized and characterized using IR, 1H-NMR, Mass spectra, and elemental analysis. Compounds were screened for in vitro antimicrobial activity against B. subtilis, E. coli, C. albicans, and A. niger, showing significant antibacterial and fungicidal potential. In vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv was highest for compound 4f (76% inhibition). Selected compounds were evaluated for anticancer activity against 60 human tumor cell lines; compound 4e showed selective activity against leukemia cell lines. © 2013 Elsevier B.V., All rights reserved.