The effect green vegetable on fecal excretion of polychlorinated dibenzo-p-dioxin (PCDD) congeners and polychlorinated dibenzofuran (PCDF) congeners was examined in male rats. The rats were administered 10% vegetable diets or a basal diet containing 0.2 ml of the causal rice-bran oil of Yusho that had occurred in the Southwest part of Japan in 1968 and kept on the same diet for five days. The fecal excretion of 2,3,7,8-T4CDD and 2,3,4,7,8-P5CDF in the group fed with Komatsuna, Mitsuba, Spinach and Perilla were 7.6-11.6 and 6.5-9.4 times higher, respectively, than that in the group fed with a basal diet. The fecal excretion of 2,3,7,8-T4CDD and 2,3,4,7,8-P5CDF in the group fed with Kale, Chinese chive, Shungiku, Chingentsuai, Green lettus and Sweet pepper were 3.3-4.8 and 4.3-4.5 times higher, respectively, than that in the basal group. The fecal excretion of 2,3,7,8-T4CDD and 2,3,4,7,8-P5CDF in the group fed with Chinese cabbage, Broccoli, Onion, Welsh onion, Cabbage and Celery were 1.6-3.0 and 1.2-1.3 times higher, respectively, than that in the basal group. A correlation between Chllophyll consumption and fecal excretion of PCDD and PCDF congeners was highly significant (p < 0.01). Next, we investigated the fecal excretion of PCDD and PCDF congeners from day 8 to day 35 in rats administered with 0.5 ml of the rice oil. The fecal excretion of 2,3,7,8-T4CDD and 2,3,4,7,8-P5CDF in the group fed with Perilla, Kale and Spinach were 3.1-4.9 and 3.0-3.6 times higner, respectively, than that in the basal group. The presents results suggest that the green vegetables might be useful in treatment of humans exposed to PCDD and PCDF congeners.