Formation of silver nanoparticles (AgNPs) by a biological route employing Crossandra infundibuliformis leaf extract has been investigated. The silver nanoparticles were formed in 1 h by stirring at room temperature. In this case, yellowish brown color was developed. Formation of AgNP was confirmed by surface plasmon spectra and absorbance peaks at 457 nm. Crystalline nature of the nanoparticle was face centered cubic (fcc) structure. The AgNPs formed were flake-like in shape and the average particle size was about 38 nm. © 2011 Elsevier B.V. All rights reserved.