Deep eutectic solvents as a new type of eco-friendly solvents have attracted attention in chemistry, medicine, and other fields for the extraction and separation of target compounds from medicinal plants. Deep eutectic solvents are easy to prepare and have many advantages as solvents, such as chemical inertness with water, low cost, easy biodegradability, and pharmaceutically acceptable toxicity. In this study, a deep eutectic solvent made up of choline chloride-glycerol (1:2) was used for the extraction of flavonoids from Catharanthus roseus plant parts (flower petal, leaves, stem, and root). The highest amount of phenolic content was detected in flower petal, that is, 194.50 mg GAE/g. In DPPH test, the maximum amount of antioxidant activity determined in the flower petal was 73.13%; IC₅₀ was calculated by using a linear regression equation; IC₅₀ value of the standard, stem, root, leaf, and flower petal was 13.22, 90.44, 83.93, 120.14, 79.49 μg/ml, respectively. The result of this research is that Catharanthus roseus has a compatible antioxidant activity. This can be helpful for the treatment of diseases caused by free-radical oxidative stress.