Abstract: The mechanism of action of the leaf extracts of V. tenoreana on some pathogens was investigated. The pathogens included Staphylococcus aureus (NCIB 67), Bacillus subtilis (NCIB3610), Pseudomonas aeruginosa (NCIB 950) and Escherichia coli (NCIB 86). Crude extract of the leaf was obtained using methanol and distilled water (in ratio 2:3 v/v). The extract leaked potassium and protein from the cells of S. aureus, B. subtilis, E .coli and Pseudomonas aeruginosa. Protein was leaked increasingly from the bacterial cells during the first 60 mins of interaction, after which a continuous decrease in the protein leakage began. However, the leakage of potassium ions from the cells of the pathogen followed an increasing trend throughout. The leaf extract leaked 0.30 M of potassium from S. aureus at ten minutes interaction, while as much as 103.87 M was leaked at 60 min interaction from the same organism.