Eight cultivars of poinsettia, Euphorbia pulcherrima Willd. ex Klotzsch., were exposed to sulfur dioxide under controlled-environment conditions. A new cultivar, ‘Ruff & Reddy’, showed the most overall tolerance while ‘Rudolph’ and ‘Mikkel Blaze’ were least tolerant. The bracts of ‘Annette Hegg’ were injured most by sulfur dioxide, whereas the bracts of ‘Ruff & Reddy’ and ‘Eckespoint C-1’ were not visibly injured at the dosage levels tested. The wide range in tolerance to SO2 among the 8 different genotypes indicates a potential for breeding and selection of tolerant cultivars.