Abstract: The bio-preservative effects of leaf of bitter leaf extract (Vernonia amygdalina), respectively on 2 palm wine types namely, palm wine with bitter leaf extract and palm wine without bitter leaf extract from Makurdi, Nigeria was evaluated. Samples were analysed by adding 1 mL of bitter leaf extract into 1000 mL of palm wine and a control of 1000 mL without bitter leaf extract was monitored at interval of 12 h. The microbiological and biochemical changes of the palm wine brands were determined, palm wine without bitter leaf extract were found to support more heterotrophic and coliform populations than the palm wine with bitter leaf extract, while the later contained more yeast species. Identification of isolated species revealed the presence of Bacillus sp., Micrococcus sp., Lactobacillus sp., Saccharomyces sp., Bacillus sp., Streptococcus sp., Staphylococcus sp., Pseudomonas sp., Zygomonas sp., Neurospora sp., Aspergilus niger, Aspergilus fumigate and Penicillium notatum. The time, frequency and percentage of palm wine sample without bitter leaf extracts on nutrient, MacConkey and sabouraud destrose agar and their CFU mL–1 shows the highest at total time of 156 h has the frequency of 73, the percentage was 100% with the total microbial count of 73.0x105 CFU mL–1, while palm wine with bitter leaf extract show the lowest at total time of 156 h has the frequency of 43, the percentage was 100% with the total microbial count of 43.0x105 CFU mL–1. The one with bitter leaf extract have lower microbial count because bitter leaf extract (V. amygdalina), lowered the bacterial and fungal growth because its serve as an antimicrobial agent that inhibit microbial growth.