Objective: The present study deals with the effects of Schleichera oleosa (Lour.) Oken leaf extracts on helminths and alpha-amylase inhibition. Identification of phytochemicals and physicochemical analysis were also performed.Methods: Different concentrations (25, 50, and 100 mg/ml) of petroleum ether, acetone, chloroform, ethanol, and aqueous extracts of the leaf were used to examine the effects. For the evaluation of in vitro anthelmintic activity, several earthworms (Eisenia fetida, Perionyx excavates, and Pheretima posthuma) and nematode (Ascaridia galli) were taken, while albendazole was used as a standard drug and Tween 80 (3%) in normal saline (0.9% NaCl) was considered as a control treatment. In vitro alpha-amylase inhibition of different extracts (10–100 mg/ml) was done spectrophotometrically by dinitrosalicylic acid - starch azure method.Results: The ethanolic extract showed the maximum presence of phytochemicals among all the extracts, which included alkaloids, tannins, flavonoids, saponin glycosides, phenolic compounds, resins, and amino acids. The outcomes of the determination of physicochemical parameters and fluorescence characters provided the satisfactory results. Significant anthelmintic activity was established by the ethanolic and aqueous extracts of the leaf among all the extracts and the responses, so observed, were dose responsive. Inhibition of alpha-amylase by ethanolic and aqueous extracts was significant with the IC50 value of 36.63 and 73.94 μg/ml, respectively, when compared to standard acarbose.Conclusion: The ethanolic extract was the more potent candidate for both the effects, and the effect of extract was best against A. galli, P. posthuma, and E. fetida at higher concentration. Isolation and characterization of therapeutic constituents would be the future interest.