AbstractThe chemical composition of the essential oils from the leaves and fruit ofEucalyptus camaldulensisgrown in Mersin, Turkey was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The biological activities (antibacterial and antifungal) were examined using the agar well diffusion method. The main leaf oil constituents werep-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%). The main constituents of the fruit oil were eucalyptol (1,8-cineole) (34.5%),p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). Our results showed that both types of oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. The leaf and fruit essential oils ofE. camaldulensissignificantly inhibited the growth of Gram-positive (Staphylococcus aureusandBacillus subtilis) and Gram-negative (Escherichia coliandStreptococcussp.) bacteria (p<0.05). The oils also showed fungicidal activity againstCandida tropicalisandC. globrata. Leaf essential oils showed more activity than fruit essential oils, probably due to the higher p-cymene concentration in leaves.