Healing with traditional herbal remedies is invaluable in avoiding the toxicity of synthetic drugs. The ethanol stem bark extract of Boswellia dalzielii (Burseraceae) was chosen for the experiment to estimate the phytochemical constitution and their antioxidant activity using ferric reducing power assay (FRAP) and 2,2- diphenyl-1-piccrylhydrazylhydrate (DPPH) radical scavenging activities and 50% inhibitory concentration (IC50) was calculated and compared with the standard synthetic drug ascorbic acid. Phytochemical screening was used to check the presence of bioactive compounds known as phytochemicals in the stem bark extract. In addition, further analysis was carried out using GC-MS. The result indicated the presence of Tannins, Saponins, Steroids, Glycosides, Alkaloids Carbohydrate Resins and Flavonoids. The antioxidant activities for the ethanol extract were recorded as IC50 1.99 using DPPH. FRAP assay exhibited antioxidant capacity was 4.78 with EC50. The proximate analysis revealed proportions of nutrients and their contents present. Among many bio-active compounds determined in the GC-MS analysis of the stem bark extract were alpha. -Amyrin, beta Amyrin octadecanoic acid, d-Allose. 6-epi-shyobunol and Urs-9(11) -en-12, methyl ester are the major compounds that might contribute to biological activities such as antioxidant, anti-microbial, anti-cancer, anti-diabetic, and anti-inflammatory properties.