Vegetables are considered a rich source of such antioxidants as phenolics, carotenoids, flavonoids, and vitamins, which are frequently added to stop the process of oxidation in processed food and biological systems. This work aimed to investigate the antioxidant potential of vegetable waste (garlic, onion, and cauliflower). The extracts of vegetable waste were prepared by two solvents – 80% methanol and 80% ethanol – and were appraised for their antioxidant potential. Total phenolic contents (TPC) of these vegetable waste extracts were in the range of 2.23-16.12 mg Gallic acid equivalents/gram (GAE/g) of dry weight (DW), while total flavonoids were in the order of 0.24-2.13 mg catechin equivalent/gram (CE/g) of DW. Maximum inhibition capacity and maximum scavenging activity was displayed by ethanolic extract of onion waste. The onion waste extract compared to others also showed high reducing power (1.27) as it had higher intensity of color. This analysis declares onion waste with maximum value of TPC, total flavonoids content (TFC), 2, 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), and the percentage of age inhibition.