Fruit yield and quality were determined in field plots of tomato (Lycopersicon esculentum, Mill.) inoculated with Xanthomonas campestris pv vesicatoria (Doidge) Dye at the 3-4 true leaf stage (early inoculation), or 10 days after first fruit set (late inoculation), and in uninoculated control plots. Early inoculation reduced yields, especially of large-sized fruit. In one of 2 experiments, yield of large-sized fruit was also reduced by late inoculation. Bacterial spot on fruit was responsible for some marketable yield loss in both experiments. Sunscald was significantly increased in early inoculation plots in one of the experiments. No disease effects on crop maturity or total number of fruit harvested were found. Yield losses were more severe than could be accounted for by lost and diseased foliage alone.