Because they are dramatic and intriguing, chemiluminescence demonstrations have been used for decades to stimulate interest in chemistry. One of the most intense chemiluminescent reactions is the oxidation of diaryl oxalate diesters with hydrogen peroxide in the presence of a fluorescer. In typical lecture demonstrations, the commercially available oxalate diesters, bis(2,4,6-trichlorophenyl)oxalate (TCPO) or bis(2,4-nitrophenyl)oxalate (DNPO), are used. These compounds are dissolved in volatile, nonbiodegradable, and toxic organic solvents. The products of the chemiluminescent reaction are carbon dioxide and either 2,4,6-trichlorophenol or 2,4-dinitrophenol, both of which are aquatic and terrestrial toxins. To avoid these toxic pollution sources, we have designed an impressive chemiluminescent reaction employing divanillyl oxalate, 1.0 M NaOH, hydrogen peroxide, a fluorescer (e.g., perylene), and triacetin as solvent. The products of this "greener" chemiluminescent reaction are carbon dioxide and vanillin. Both vanillin and triacetin are biodegradable and possess minimal toxicity. This environmentally friendlier chemiluminescent reaction is visible in a darkened room for as long as 45 minutes. (Contains 2 schemes.)