The Asteraceae family is one of the largest flowering plant families and is known for its antioxidant, anti-inflammatory, and antimicrobial activity. Their pharmacological effects can be related to their range of phytochemical compounds, including polyphenols, phenolic acids, flavonoids, acetylenes, and triterpenes.  In this study, Sunflower (Helianthus annuus), Gazania (Gazania rigens), Gaillardia (Gaillardia pulchella), Zinnia (Zinnia elegans), and Chrysanthemum (Chrysanthemum morifollium) were evaluated for their antioxidant activity using the DPPH free radical scavenging assay. Total phenol content (TPC) and the gene expression profiles of some antioxidant-related genes, including ascorbate peroxidase 3 APX3, catalase CATA1, and Phenylalanine ammonia lyase PAL, were also analyzed. Results revealed that Sunflower and Chrysanthemums plants had the highest phenolic contents of about (3.26±0.39 and 2.99±0.22 mg GAE/g), respectively. The expression of PAL gene was about 4-fold and 2-fold higher in Chrysanthemums and Zinnia s' flowers, respectively, in comparison to the sunflowers. APX3gene expression was upregulated in Chrysanthemum, Gazania, and Gaillardia ‘s leaves in comparison to the Sunflowers'. Our results give an insight into the antioxidant potential of some uncommonly used plants of the family Asteraceae.