Garden cress (Lepidium sativum L.) is an annual herb that is native to West Asian. Although it is now planted all over the world. It is grown for its seeds, as it is the most widely used part. The chemical composition of garden cress (GC) seed powder was examined. The results revealed that GC contains10.39% moisture,22.42% protein,25.57% fat and 22.19% carbohydrates. Moreover, the recorded ash and fiber content were 9.60% and 9.83%, respectively. Also, phytochemical analysis of GC extracts showed that plant extracts contain tannins, saponins, alkaloids, terpenoids, flavonoids, phenols, phytosterols and sterols. The highest amount of total phenolic was found in the ethanol extract, which gave 25.13 µg/ml of gallic. While the highest amount of total flavonoids was found in the methanol extract, which gave 41.30 µg/ml of rutin. The HPLC analysis was carried out on the ethanolic and methanolic extracts of garden cress. Seven phenolic acid compounds have been detected in ethanolic extract including catechol, syringenic, cinnamic, caffeic, pyrogallol, gallic and ellagic, while nine phenolic compounds have been detected in methanolic extract, including catechol, syringenic, cinnamic, caffeic, gallic, ferulic, salicylic, ellagic, and benzoic. Furthermore, the methanol extract of garden cress showed the highest DPPH scavenging activity compared to ethanol extract. It can be concluded that GC seeds and their extracts can be used in different fields such as nutritional supplements and medical fields because it is rich in antioxidants.