Genus Bidens contains numerous compounds including phenylpropanoids, alkaloids, triterpenoids, flavonoids, and organic acids, with flavonoids being one of the main effective compounds. Significant flavonoid content has been reported in various Bidens species, such as 37.67 mgQE/g in the methanol fraction from B. engleri. HPLC analysis of B. tripartita revealed total flavonoid contents being 1.230% in herbs and 0.649% in flowers. B. pilosa L. has a complex flavonoid profile comprising aurones, chalcones, flavanones, flavones, and flavonols. It has been widely used in Chinese ethnopharmacology for treating malaria, hepatitis, diabetes, inflammation, digestive disorders, and hypertension. Various studies have identified numerous flavonoids in B. pilosa, including astragalin with anticandidal properties and a variety of kaempferol and quercetin derivatives. B. cernua L. has also been studied for its flavonoid content, revealing compounds such as tilitanin, cynaroside, and maritimetin. B. pilosa var. radiata Sch Bip. contains flavonoid glycosides with significant antioxidant and anticancer activities. B. parviflora Willd. has been analyzed for its flavonoid profile, yielding compounds like luteolin 7-O-β-D-neohesperidoside and quercetin 3-O-β-D-glucoside. B. humilis is reported to contain new natural flavonoids such as luteolin 7-O-β-D-glucopyranosyl-(1 → 6)-β-D-galactopyranoside. B. biternata (Lour.) Merr and Sherff and B. bipinnata L. have also been recognized for their significant flavonoid content and associated health benefits. Advances in pharmacological studies have revealed that these compounds in Bidens species exhibit antibacterial, antioxidant, anti-inflammatory, hypolipidemic, analgesic, hepatoprotective, antitumor, and antidiabetic activities.