Phaseolus vulgaris L. cv. Blue Lake plants were grown in sand culture at three temperatures, and fed with nutrient solution containing 1.3 or 32 mg/liter sulfur (S). Plants were fumigated twice with ozone at 50 parts per hundred million (pphm) for 2 h.Intensity of phytotoxicity was markedly lower in plants grown at the high S rate. Ozone reduced chlorophyll content of plants grown in low S at 25/20 and 30/25°. With the high S treatment, however, ozone had no significant effect on chlorophyll content, particularly at the lower temperatures. Irrespective of S nutrition, ozone had no effect on total soluble carbohydrate content. Ozone effects on plant growth depended on plant part, growth temperature, and S nutrition.