Introduction. The nutritional and functional qualities of wild and cultivated Mexican serviceberry have not yet been reported. This species could have similar potential for commercialization to that of Saskatoon berry (Amelanchier alnifolia Nutt.). Materials and methods. Wild and cultivated fruits at two maturity stages were assessed for CIE Lab color, fruit size, titratable acidity and total soluble solids. Also, chemical composition and mineral contents were determined. In addition, vitamin C and simple phenols were assessed. Total soluble phenols, condensed tannins and anthocyanins as well as Trolox antioxidant activity and oxygen radical antioxidant activity were determined. Results. Fruit size, titratable acidity, total soluble solids, iron and simple phenols were higher in fruits of cultivated plants than in those of wild plants. Total fiber, calcium, vitamin C, total soluble phenols and condensed tannins were higher in wild fruits. Wild and cultivated serviceberry showed higher Trolox antioxidant activity compared with oxygen radical antioxidant activity. Caffeic, chlorogenic, coumaric and syringic acids and rutin were the predominant simple phenolics; they comprised from 59.3% (cultivated overripe fruit) to 76.9% (wild ripe fruit) of the sum of simple phenolics. The antioxidant activity of wild and cultivated fruit (258.3–699.2 mmol·kg–1, fw) is up to 3.8 times higher compared with those of fruits commonly consumed. Conclusion. Contents of antioxidant compounds and the outstanding antioxidant activities of wild and cultivated Mexican serviceberry make this species a natural resource that could contribute to health.