Abstract: The objectives of this study were to assess the yield and characteristics of by-products from different agro-industries in Khorasan Razavi Province. In a survey the potential by-products generated by the provincial agro-industrial sector was evaluated. The total amount of by-products generated by 127 factories was 102,918 tons year^-1 (DM (%) basis). More than 80% of the agro-industries were established in the provincial capital city of Mashhad and the others (20%) located on 19 cities. About 61% of the by-products were available all year round, the rest in summer and fall seasons. The major by-products were tomato pomace, grape pomace, slaughter house by-products, apple pomace and pistachio by-products. Generally, CP content of the most by-products was high mainly of those products from animal origin sector. The CP content of dried fruit and vegetable by-products ranged between 8 and 22%, of human food industry by-products between 9-25% and of animal origin by-products between 17-69%. Degradability values indicated feeding value of the studied by-products from both human food industries and animal origins were high in comparison with those of fruit and vegetable processing section. Almost all agro-industrial by-products had high moisture content and were prone to spoilage and their transportation, storage and handling were difficult and costly. However, it was concluded that most of by-products were more suitable for ruminant animals. More accurate researches and data on nutritional characteristics, appropriate processing methodology, practical and the cost-effective methods on inclusion these by-products into the diets for animals are required.