The essential oil from the leaves of Hoslundia opposite was extracted by hydrodistillation. GC/MS analysis of the volatile oil showed that it contains largely the sesquiterpenes and sesquiterpene alcohols. The essential oil was tested against eight different bacterial species and one fungal species. The antibacterial and antifungal properties of the essential oil from Hoslundia opposite were determined by using seeded agar plates with wells into which was placed the oil, and flasks of yeast extract and sucrose broth for mycelial growth of Aspergillus niger. After incubation for 24 hours, the diameter of the inhibition zone was measured for the antibacterial tests and after seven days, the dry weight of the mycelia was measured and a percentage of inhibition calculated using controls where no samples were added. The results obtained showed that the essential oil from this plant has significant activity against Aspergillus niger, Acinetobacter calcoacetica, Brochothrix thermosphacta and Flavobacterium suaveolens. These were most affected by the volatile oil from Hoslundia opposita.