The purpose of this study is to develop a novel method for colorimetric sensing and selective determination of the non-chromophoric drug, pregabalin using unmodified silver nanoparticles (AgNPs). Silver nanoparticles are prepared by reducing 0.64 mM silver nitrate with 0.1% w/v sodium borohydride and stabilizing the nanoparticles with 10 mM sodium citrate under vigorous stirring. The citrate-capped silver nanoparticles dispersed in water exhibit a bright yellow color owing to the electrostatic repulsion between the particles due to the presence of negatively charged surface and have a localized surface plasmon resonance band at 390 nm. Addition of positively charged pregabalin prepared in acetate buffer pH 3.8 induced rapid aggregation of silver nanoparticles through electrostatic interactions with the negative charge on the particle surface. This caused a decrease in the absorbance at 390 nm and the color of the colloidal solution turned from yellow to green upon aggregation. The decrease in absorbance at 390 nm is directly proportional to the concentration of pregabalin with a linearity range of 100 – 500 μg mL-1, a limit of detection of 19 μg mL-1 and a limit of quantitation of 57 μg mL-1. The method was applied for determination of pregabalin in Lyrica® capsules with mean %recovery ± standard deviation of 97.809 ± 1.396. The method is simple, rapid, and cost-effective and can be used for determination of pregabalin in bulk and in its pharmaceutical preparations.