The purpose of the study was to evaluate the properties of by-products obtained from the oil industry, to identify the content of bioactive compounds and to test the safety of their reintroduction in the food industry. Three sunflower meals obtained after cold-pressing of whole (WSM), partially dehulled (PSM) and total dehulled (TSM) sunflower seeds were used. A higher protein, ash and fiber content was obtained for WSM, followed by PSM, and TSM meals. Conversely, the lipid content was higher in TSM and PSM, and lower in WSM meals. Sunflower meals are important sources of unsaturated fatty acids (more linoleic than oleic acid), the content ranging between 82.74 and 86.72%. Additionally, sunflower meals represent a significant source of compounds with antioxidant activity. TSM showed the highest concentration of total polyphenols and total flavonoids, while WSM the lowest. The values of antioxidant activity were higher for TSM compared to PSM and WSM. The weak cytotoxic activity at concentrations lower than 6.25 mg/mL, as well as cell viability which is not affected by the action of PSM and TSM but even increases in the case of WSM, give sunflower meals the potential to be added as ingredients in the production of functional foods.