The article assesses the biotechnological potential of the minor parts formed when cutting rainbow trout. It was found that the share of secondary parts accounts for 52.2%. This result allows showing the relevance and expediency of developing measures for their rational use and involvement in the production of products for various purposes. Research has been carried out on the chemical, amino acid, and mineral compositions of the minor parts of rainbow trout. The study results showed that the minor parts of rainbow trout have a high biological value of protein. The content of all essential amino acids is rich in macro-and microelements. It is shown that a high mass fraction of protein (15.41-58.46%) in the minor parts of rainbow trout opens excellent prospects for organizing their collection, accumulation, and processing.