Seventy-five Lohman, two weeks of age broiler chicks were used to examine the effects of substitution of raw and treated linseed meal instead of soybean meal protein on broiler performance during starter and finisher periods. Raw linseed meal was treated by boiling in acid solution (HCI 0.1 N), then, soaking over night in copper sulphate solution to minimize the level of some toxic or antinutrional factors. The results indicated that boiling treatment was effective in reducing phytic acid, tannic acid and cyanide ion contents of linseed meal. Treated linseed meal could be replaced effectively and economically up to 25% instead of soybean meal protein in starter and finisher diets without adverse effect on broiler performance carcass traits. This level realized the most relative economic efficiency.