Free radicals which are normal byproducts of normal metabolism, can cause oxidative stress resulting in DNA damage and gene mutation. When there is an excess of oxygen or insufficient reduction, reactive oxygen species (ROS) like superoxide anions, hydroxyl radicals and hydrogen peroxide are produced. ROS are essential for various important biological processes in organisms including phagocytosis, cell growth regulation, intracellular signaling and synthesis of biologically active substances. Leaf extract of Lagenaria breviflora was examined for its secondary metabolites, antioxidant properties and antibacterial effects on Escherichia coli (ATCC28923), Staphylococcus aureus (ATCC28923), Enterococcus faecalis (ATCC29212) and Bacillus subtilis (ATCC6051). Chemical analysis of the plant leaves showed that they contained sesquiterpens, steroids, terpenoids, alkaloids and tannins. The quantitative assessment of the secondary metabolites showed specific concentrations of various compounds in the leaf extract of Lagenaria breviflora. This study showed that the antioxidant activity demonstrated using DPPH (2, 2-diphenyl-1-1-picrylhydrazyl) scavenging assay increased with higher concentrations of the leaf extract. The susceptibility of the test organisms to the plant extract was evidenced by the zones of inhibition they produced. Zones of inhibition of 16.0±1.2mm, 17.5±0.3, 19.2±0.4mm, and 16.5±2.3mm were recorded against Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis respectively when methanol extract of Lagenaria breviflora were assayed against the bacteria. The results indicated that the bacteria were vulnerable to the plant extract. This study suggests that the compounds present in leaf extract leaf extract Lagenaria breviflora have the potential for use in chemotherapy applications.