© 2022 Wiley Periodicals LLCMedicinal plants accumulate and synthesize minerals and phytochemicals for treating human diseases. The objectives of this work have been to characterize the polyphenol and mineral contents of 25 medicinal plant leaves grown in the urban environment of India to know their antioxidant, nutritional potentiality, and ease of contamination with toxic elements. Total polyphenol (TPh) and flavonoid (Fla), and mineral concentrations were determined spectrophotometrically and by X-ray fluorescence spectroscopy, respectively. The leaves under study were found to be rich in polyphenols, nutrients (P, S, Cl, K, Mg, Ca, Mn, Fe, Cu, Zn, and Mo), and other metals (Rb, Sr, Ba, Al, Ti, V, Cr, Co, As, Se, and Pb), with concentrations ranging from 1.28 to 3.96 g 100 g−1, from 219.8 to 7159.9 mg 100 g−1, and from 4.3 to 334.0 mg 100 g−1, respectively. Maximum polyphenol and mineral (nutrient and other elements) concentrations were detected in Melia azadirachta L., and Solanum lycopersicum L. leaves. Enrichment factors, correlations among elements, sources, health hazards associated with heavy metals, and potential applications of plant leaves are also discussed.