The aim of the present study is to investigate the antioxidant activities of crude methanolic extract and its different fractions obtained from Algerian Crataegus azarolus leaves and flowers using different tests such as DPPH (1, 1-diphenyl-2-picrylhydrazyl radical), reducing power and beta-carotene assays. Furthermore, a preliminary phytochemical screening was performed using standard protocols. Total phenolics and total flavonoids contents of the extracts were measured by Folin Ciocalteu and Aluminium chloride methods respectively. The obtained results indicated that ethyl acetate fraction (EAF) showed the highest DPPH radical scavenging activity with an IC50 value of 9.72 +/- 0.102 mu g/ml, followed by crude methanolic extract (CME) and diethyl ether fraction (DEF) with an IC50 value of 20.96 +/- 0.340 and 68.69 +/- 2.490 mu g/ml, respectively. However, the ethyl acetate fraction showed a good reducing power (EC50=30.96 +/- 0.563 mu g/ml) as compared to other fractions. In beta-carotene/linoleic acid assay, the best inhibition was found in chloroform fraction (CHF) with an IC50 of 65.45 +/- 1.027 mu g/ml. The phytochemical screening showed the presence of alkaloids, tannin, anthraquinones, steroids and triterpenes. Total phenolics varied from 2.83 mg to 111.96 GAE/g in each fraction. The ethyl acetate fraction contained the highest amount of flavonoids (5.87 +/- 0.255 mg QE/g of fraction) compared to other fractions. As a conclusion, the results of the present study indicate that the aerial part extracts of Crataegus azarolus is a good source of natural antioxidant constituents. (c) All Rights Reserved