The subject of this study was to figure out the effects of lentil by product (LP) on growth performance and carcass traits of the white heavy turkeys. To accomplish this goal, a total of 210 day old big-6 turkey chicks were used. The birds were divided into 7 seven groups with 3 replicates. The 1st, 2nd, 3rd, 4th, 5th, 6th and 7th groups received 0, 5, 10, 15, 20, 25 and 30 % lentil by product, respectively. All the diets were made as izonitrojenic and izocaloric. The highest live body weights of males and females were observed in the control group at the end of the 15th week, which was the time of slaughtering of females, however the differences between the control and the 2nd, 3rd and 4th groups were not significant (p>0.05). The same differences continued for males at the end of the 17th wk of age, which was the time of slaughtering of males. Similar results were observed in carcass traits, as well. The best FCR was noted in the control group and it was significantly (p<0.05) different than in the treatment groups. The lowest and highest feed intake was observed in the 7th and 3rd groups. No significant differences were observed between control and all treatment groups.