The goal of this work was to evaluate the chemical constitution and health-promoting potential of 12 varieties of Chaenomeles × superba, speciosa and japonica leaves. Carotenoids, chlorophylls, triterpenes, sugars, polyols and acids were analyzed quantitatively and qualitatively using high pressure liquid chromatography (LC) coupled with mass spectrometry (MS), while the mineral profile was determined using atomic absorption spectroscopy (AAS). Moreover, the in vitro anticholinergic potential (inhibition of acetyl-cholinesterase (AChE) and butyryl-cholinesterase (BuChE)) and antioxidant (ABTS, FRAP, ORAC) capacity were evaluated. For the first time in Chaenomeles genotypes 26 carotenoid derivatives and 22 chlorophyll derivatives were identified. Some varieties contained high amounts of carotenoids and chlorophylls (Ch. × superba 'Colour Trail', 'Nicoline', 'Pink Lady', 'Texas Scarlet'), and triterpenes (Ch. speciosa 'Simonii', 'Rubra', and Ch. × superba 'Colour Trail', 'Nicoline') and showed high ORAC antioxidant (Ch. × superba 'Pink Lady' and Ch. speciosa 'Simonii') and anticholinergic (Ch. speciosa species) activity. The studied leaves also contained sugars (3.1 to 16.5mg/100g), organic acids (3.9-8.1g/100g), and minerals (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn). In conclusion, Chaenomeles leaves show potential as a new source for the production of nutraceuticals, as well as for medical and/or cosmetic purposes.