The present study aimed to investigate the possible prophylactic and therapeutic effects of hydro-alcoholic extract of Sapindus trifoliatus on AD induced by AlCl₃ in rats. In this study thirty adult Wistar albino rats were selected and were divided into 5 groups (six each). Group I, II, III, IV & V served as normal control, negative control, test group and standard control respectively. The rats were given treatment for 30 days and behavioural parameters were determined on 1^st, 10^th, 20^th, &30^th day of treatment. After day 30^th rats were sacrificed and biochemical parameters (antioxidant levels & Acetylcholinesterase activity) were determined. This study indicated that Sapindus trifoliatus when was used for treatment of AlCl₃induced AD, it improves the behavioural & biochemical parameters. The histopathological finding in hippocampus of brain tissue neuron appears less or more like normal one when compared to the negative control