The one step synthesis of short aspect ratio gold nanorods using gamma radiation method by incorporating cetyltrimethyl ammonium bromide (CTAB) as a directing agent is reported in this communication. In present method of synthesis, isopropyl radical is selectively generated in the system by carrying out radiolysis of aqueous solution containing 2.75 × 10−2 mol dm−3 of acetone, 0.2 mol dm−3 isopropanol, 4 × 10−4 mol dm−2 Au1+ and 6 × 10−5 mol dm−3 Ag+. The isopropyl radical brings about the reduction of Au1+ to Au0, which undergoes coalescence with other Au0 resulting in formation of Au nanorods. The formation of nanorods is attributed to slower reaction of isopropyl radical with Au1+. The TEM of as-prepared nanoparticles confirmed the formation of uniform sized nanorods having aspect ratio 3.