In the present investigation, extracellular biosynthesis of silver and zinc oxide nanoparticles was investigated using Candida diversa strain JA1 isolated from waste water of milk processing unit in Vellore, Tamil Nadu, India. The biological synthesized metal nanoparticles were characterized through several analytical techniques including UVvisible spectrophotometer, X-ray diffraction pattern analysis (XRD), FE-Scanning electron microscope (SEM) with EDX-analysis (EDXA). The antimicrobial properties of biosynthesized metallic nanoparticles were tested against medically important Gram positive (Enterococcus sp. and Staphylococcus aureus), Gram negative (Escherichia coli, Salmonella sp., Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Shigella sp.) and fungal pathogenic microorganisms (Aspergillus terreus strain JAS1, Ganoderma sp. JAS4, Scedosporium sp. JAS1, Candida tropicalis and Fusarium sp.). The combined effect of antibiotics and biologically synthesized metal nanoparticles were also evaluated against clinical pathogens.