Histological changes in the thyroid and the liver of broiler chicks and laying hens fed Canadian rapeseed meal(RSM) were observed and following conclusions were made. 1. Grossly, no pathological changes were noticed in the thyroid of broiler chicks and laying hens. In broiler chicks. the liver was slightly paler in color in 12% rapeseed meal fed group. The liver of laying hens fed rapeseed meal for 24 weeks was slightly paler in color both in. 9% and 12% group, and the discoloration was also noticed in 6% group fed for 36 weeks. 2. No histological changes were observed in the thyroid of broiler chicks and laying hens fed rapeseed meal up to 12%. 3. Fatty changes in the liver of broiler chickes fed high level of rapeseed meal were milder in the group substituted for fish meal compared with the group substituted for soybean meal. 4. Fatty liver syndrom of laying hens were more severe in the group fed rapeseed meal for prolonged duration. It should be noted that 12layer were dead due mainly to the liver hemorrhage associated with fatty liver syndrome. It appears that the goitrogenous compound in Canadian rapeseed meal has nearly all eliminated through RSM breeding effort. However, a very little amount of certain compound that disturbs normal fat metabolism in the liver occurs in the rapeseed meal.