Objectives: The present study was intended to investigate possible phytochemical nature (group determinant of plant extract) and to reveal in-vitro thrombolytic, membrane stabilizing and cytotoxic activities of crude methanolic extracts of Bruguiera cylindrica leaves. Methods: Collected plant parts were cleaned, dried, and ground to obtain powdery mass. Various methanolic extracts of B. cylindrica was subjected for evaluating membrane stabilizing potentials at a hypotonic solution and heat induce condition, where thrombolytic activity assessment was done by employing Streptokinase as standard. Finally, Cytotoxicity activity was determined by Brine shrimp Lethality bioassay. Results: Phytochemical screening of methanolic extracts revealed the presence of carbohydrate(s), glycoside(s), phenol, tannin, protein(s), gum and mucilages. Crude methanolic extracts with different doses were used for in-vitro thrombolytic study and 10 mg/ml concentration of plant extracts showed moderate clot lysis (14.51±1.87%) while the standard (streptokinase) showed 59.73 ±0.97% clot lysis. The methanolic extracts exhibited significant anti-inflammatory properties at 10mg/ml concentration by both hypotonic solution and heat induced haemolysis of erythrocyte membrane i.e. 18.53±0.91% and 23.60±0.89% respectively. In contrast to vincristine sulphate the crude methanolic extracts showed moderate cytotoxic properties with LC50 value of 16.628. Conclusions: Our present study suggest that, further studies may carry on this plant extracts to build up an acceptable report in the medical science.