Averrhoa carambola L. (A. carambola) is particularly well-known for its distinctive star-shaped fruit (Star fruit), cultivated in Southeast Asia, the Indian subcontinent, and northern and southern America. Historically, it has been used for a long time to cure many ailments, including vomiting, fever, arthralgia, cough, hypertension, hangovers, chronic paroxysmal headache, hyperglycemia, and diabetic nephropathy. This study aimed to examine its preliminary phytochemical and some biological properties. For this, fresh leaves of A. carambola were extracted (hot and cold) with ethanol, which was then fractionated with n-hexane and chloroform. Following a preliminary investigation of phytochemicals, radical scavenging, membrane stabilizing, alpha-glucosidase inhibitory, and clot lysis effects were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, egg albumin model, alpha-amylase assay, and human blood clot lysis assay, respectively using suitable reference standards. The results suggest that A. carambola contains alkaloids, glycosides, steroids, tannins, flavonoids, saponins, and reducing sugars. All the organic fractions demonstrated significant (p <0.05) radical scavenging, membrane stabilizing, alpha-glucosidase inhibitory, and clot lysis activities in a concentration-dependent approach. Except for DPPH radical scavenging, the ethanol fraction showed better activities than the n-hexane and chloroform fractions. In summary, A. carambola might be a potential source of antioxidant, anti-inflammatory, hypoglycemic, and atherothrombolytic agents. Further studies are required to isolate, characterize, and establish molecular mechanisms for each component’s biological effects.