Background The identification of novel plant-based functional foods or nutraceutical ingredients that possess bioactive properties with antioxidant function has recently become important to the food, nutraceutical and cosmetic industries. This study evaluates the polyphenolic composition, identifies bioactive compounds and assays the total antioxidant capacity of Prunus mahaleb L. fruits collected from different populations and sampling years in the countryside around Bari (Apulia Region, Italy). Results We identified nine polyphenolic compounds including major anthocyanins, coumaric acid derivatives and flavonols from P. mahaleb fruits. The anthocyanin content (in some populations > 5 g kg(-1) fresh weight; FW) in the fruit was comparable to that reported for so-called superfruits such as bilberries, chokeberries and blackcurrants. Coumaric acid derivatives comprised a large portion of the total polyphenolic content in the P. mahaleb fruits. Antioxidant activities, assessed using ORAC and TEAC assays, measured up to 150 and 45 mmol Trolox equivalents kg(-1) FW, respectively. Therefore antioxidant capacity of P. mahaleb fruits is relatively high and comparable to that of superfruit varieties that are often used in commercial nutraceutical products. Conclusion Our findings suggest that mahaleb fruit (currently not consumed fresh or used in other ways) could serve as a source of bioactive compounds and therefore find interest from the functional food and nutraceutical industries, as a natural food colorant and antioxidant ingredient in the formulation of functional foods. © 2015 Society of Chemical Industry.