This study was designed to comparatively evaluate the phytochemical composition and antioxidant potentials of fruit extracts from five Crataegus taxa (C. monogyna, C. orientalis, C. pontica, C. rhipidophylla and C. turcicus)growing wild in the flora of Turkey. Antioxidant activities of the samples were investigated using DPPH radical scavenging, FRAP, CUPRAC and total antioxidant capacity tests. Total phenol, phenolic acid, flavonoid, and proanthocyanidin contents were measured spectrophotometrically. Additionally, the presence of some phenolic compounds in the extracts was investigated by LC–MS/MS. Furthermore, the extracts used for the antioxidant activity studies were standardized for chlorogenic acid and hyperoside by HPTLC densitometry. Among the tested extracts, C. turcicus contained the highest phenolic (398.48 ± 0.98 GAE/g extract)and total flavonoid contents (23.87 ± 2.74 QE/g extract)content while C. monogyna contained by far the highest total proanthocyanidin (175.65 ± 10.59 EGCG-E/g extract), hyperoside (0.42%)and chlorogenic acid (0.90%)contents. Crataegus monogyna exhibited the highest antioxidant activity in FRAP, CUPRAC, and TOAC tests. Good correlation was found between the phenolic content and antioxidant parameters. This is the first report related with comparison of these five species in respect to phenolic profile and antioxidant activity.