Agricultural plants viz. chick pea, black gram and green gram were exposed to various concentrations of Ag(I) (50, 100, 150 and 200 mg/L). Significant decrease in germination percentage and growth of the seedlings were noted with the increase in Ag(I) concentration. Toxic effects of Ag(I) on plants were reflected by, an increase in malondealdehyde level (MDA) which is an index of lipid peroxidation and reduction of photosynthetic pigments. Ag(I) toxicity resulted in a significant hyperactivity of antioxidant enzymes viz. superoxide dismutase (SOD) and catalase in different parts of the plant. The activity of ascorbate peroxidase showed a decrease with an increase in concentration ofAg(I). Toxicity of Ag(I) on different microorganisms viz. Pseudomonas aeruginosa , Azospirilium, Saccharomyces cerevisiae and Trichoderma viride were assessed. The colony count (bacteria) and hyphal growth (fungi) of the test organisms were found to decrease with increase in concentration of Ag(I).