Many students find product prediction in ozonolysis reactions of alkenes and alkynes difficult, and they often have greater difficulty discerning the starting compounds when presented with ozonolysis products. The mnemonic device suggested here can help students figure out what the ozonolysis product (or products) will be. Once mastered, this mnemonic can help students identify unsaturated compounds that could have given rise to the ozonolysis products. (Contains 1 figure.)