Blueberry (Vaccinium myrtillus L.) is a perennial species belonging to the Ericaceae family. In recent years, the consumption of the fruit has increased in the market due to its rich chemical composition and beneficial effects on human health. For this reason, this type of fruit is popular not only for fresh consumption, but also processed into various products such as juices, jams, dried fruits and the like. Processing of certain blueberry products, especially juice, leaves a large amount of organic residues that are classified as waste. Organic residues are a by-product left behind after processing a certain type of fruit. Depending on the type of fruit, they consist of the remains of the pulp, stem, skin, seeds, etc. As a type of fruit, blueberries are characterized by their rich nutritional composition, rich in numerous specialized metabolites, especially anthocyanins. Anthocyanins are particularly abundant in the skin of blueberries, giving them a specific blue-violet color and standing out as powerful antioxidants. Therefore, blueberry pomace is a valuable source of nutrients, the utilization of which is of great importance. Nowadays, there is an increasing research on new process technologies for its extraction, the main objective of which is to obtain a higher yield in the shortest possible time, saving energy and preserving the nutrient composition of the final product, i.e. maintaining its quality. One of these modern, non-invasive technologies is high-intensity ultrasound. Therefore, an attempt was made to determine the optimal conditions for ultrasound-assisted extraction to preserve the nutrient composition of the organic residues of blueberries. The highest levels of vitamin C (120.7 mg/100 g fresh weight), total phenolics (801.84 mg GAE /100 g fresh weight), non-flavonoids (527.24 mg GAE /100 g fresh weight), flavonoids (374.72 mg GAE /100 g fresh weight), anthocyanins (159.29 mg/L) and antioxidant capacity (2540.84 μmol TE /L) were found in the ultrasound treated sample compared to the conventionally treated samples. The type of solvent also had a significant effect on the isolation of certain specialized metabolites from blueberry pomace, with the combination of 60% ethanol with the addition of 1% acetic acid having a positive effect on the ultrasound-assisted extraction of phenols, flavonoids, and antioxidant capacity, while 20% ethanol with the addition of 1% acetic acid had a positive effect on vitamin C content. 20% ethanol also had a positive effect on anthocyanin content in ultrasound-treated samples. In classical extraction, 60% ethanol with the addition of 1% acetic acid had a positive effect on the content of vitamin C, phenols, non-flavonoids, anthocyanins and antioxidant capacity, while 60% ethanol had the best effect on the total flavonoid content. In ultrasound-assisted extraction, several amplitude and time variables had a significant effect on the yield of certain specialized metabolites. Thus, longer treatment time (12 minutes) and higher amplitude (40%) had a positive effect on total vitamin C, phenolics, nonflavonoids, flavonoids, anthocyanins, and antioxidant capacity. In conclusion, the extracts prepared from the organic residues of blueberries are nutritionally very valuable products, with significant content of specialized metabolites, thus possessing numerous potential functional properties and benefits for the human body. High-intensity ultrasound has been shown to be extremely effective in isolating bioactive compounds from blueberry pomace, so this process technology can be considered potentially suitable for further recovery of organic residues, whether for the needs of the food or pharmaceutical industries.