Plants have very high potential as alternative source of bio-reducing and capping agents in nanoparticles (NPs) synthesis. Silver nanoparticles (AgNPs) were synthesized from Tetrapleura tetraptera leaf extract. The UV-vis spectrophotometer was used to observe the formation of the NPs at various time intervals and ratios of leaf extract to AgNO3 solution. The properties of the AgNPs synthesized were characterized by FTIR and Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDX). Antimicrobial activities of the AgNPs synthesized were evaluated against ten human pathogens using agar well diffusion method. The rate of formation of the AgNPs was shown to increase with respect to time and ratio of leaf extract to AgNO3 solution. The EDX result showed signal energy peak for silver atom at 3.0-3.8 KeV. The AgNPs was characterized with FTIR peaks around 3280, 1620, 1400 and 1040 cm−1 assigned to O-H, C=O, C–O–H and C-C groups respectively, as possible stabilizing and capping groups. The AgNPs showed maximum inhibitory activity against Staphylococcus aureus, Escherichia coli and Salmonella sp.