Abstract: To evaluate of the factors for culling of the Holstein dairy cows in an industrial herd in Tabriz, data of the reasons for deleting is divided in seven groups such as financial factors, infertility and reproduction problems, low milking cows, mastitis and udder problems, lameness, digestive system diseases, etc. At all, 2458 Holstein cows in 9 herds have evaluated. Selling the cow for the milk, infertility and low milking cows were the important reasons for culling that were 127 and 78 from 326 cows in order. The fourth reason for deleting was mastitis and udder problems that include 21 cows. The fifth factor was the digestive system diseases with 16 cows. The voluntary reason for culling was the selling cows plus low milking cows that was 56% of the culled cows. The most involuntary culling reason was for infertility and reproduction problems that were 24% of total and 41% of involuntary culling.