Problem statement: Hawthorn comprises more than 200 species worldwide but very few species have been used medicinally. In Mediterranean region, the predominant species of the genus Crataegus is C. aronia syn. Azarolus (L). The extracts or tinctures prepared from the leaves, flowers and/or a fruit has been used traditionally for the treatment of different diseases including different cardiovascular problems. This species (C. aronia syn. Azarolus (L.)) has not been adequately studied. Thus, we aimed to investigate for the possible acute and sub-acute toxicity of C. aronia syn. Azarolus (L.) on Wistar albino rats. Approach: The phytochemical screening of the aqueous extract of C. aronia syn. Azarolus (L.) was determined. Athirty six Wistar rats of both sexes weighing 180-200 g. were divided randomly into sex groups of 6 rats each. The first group was the control group and fed with equal volume of distilled water, while the other 5 groups were given single daily dose of the aqueous extract per os at different doses (100, 200, 500, 1000 and 2000 mg kg