A greener, rapid and regioselective “on water” synthesis of spirooxindole‐oxazoline by the reaction of isatin and isocyanoacetate at room temperature is described. The developed protocol has the advantage of being atom‐economical, eco‐friendly, and benign reaction conditions. Broader substrate scope, experimentally simple procedures, and easy purification of products with high yield further make this method attractive. The synthesized compounds have been fully characterized with spectral analysis.