Discovery of genus Holigarna longifolia and its traditional uses were obtained by living in forest or semi forest areas by close observations of the indigenous populations. The main aim of this study was to evaluate phytochemical screening, antioxidant and anti-microbial activity, thrombolytic activity, in vivo anti-inflammatory and neuropharmacological activity of H. longifolia leaf extract. In vitro antioxidant was evaluated by DPPH and ferric reducing power assay, Disc diffusion method was used to evaluate anti-microbial activity, thrombolytic activity was evaluated by clot lysis, determine the ability of the extracts to suppress inflammation was done using the formaldehyde-induced paw oedema test influence of the sedative activity of the drug on the forced swimming and tail flick-suspension tests were studied by using diazepam. The phytochemical screening of H. longifolia extract revealed the presence of reducing sugars, tannins, gums, steroids, glycosides, xanthoprotein and terpenoids. In DPPH the extract exhibited strong antioxidant with an IC₅₀ of 0.877 µg/mL, comparable to ascorbic acid IC₅₀ 0.839 µg/mL and in ferric reducing power assay the extract showed significant IC₅₀ value about 43.736 µg/mL. In anti-microbial tests, the highest inhibition, 19 mm was observed against Escherichia coli at 500 µg/disc, while Bacillus magaterium showed the lowest inhibition 9 mm at 250 µg/disc. In the MIC test, the extract leaves showed highest activity against E. coli (MIC = 4 mg/mL) and lowest against B. cereus, B. megaterium, and A. niger (MIC = 128 mg/mL). The extract demonstrates clot-lytic activity of 20.45 ± 1.42% versus 31.17 ± 0.65 for streptokinase. H. longifolia extract was determined to be safe in the acute toxicity trial, with no toxicity, mortality, or behavioral abnormalities in the mice. In the anti-inflammatory test, paw thickness was significantly reduced with inhibition rates of 54.22% by the dose of 250 mg/kg and 60.27% by 500 mg/kg) compared to 71.71% for the standard. Neuropharmacological tests revealed reduced immobility periods of 126.2 s in forced swimming and 145.8 s in tail suspension tests at dose of 200 mg/kg. Further studies will be needed to evaluate the full pharmacological potential H. longifolia.