The bacteriostatic and fungistatic activities of 22 volatile oils were evaluated. The results showed that the oils tested varied in their antimicrobial activity. Cinnamon oil showed the highest activity against the tested bacteria and fungi. A comparison was made between the biostatic and biocidal activity of each oil. The results also showed that the bacteriostatic results as obtained by the agar-diffusion and serial dilution methods were not always parallel. The data obtained can be made use of clinically as well as for the preservation of liquid preparations liable to microbial contamination.