The in vitro anti-Babesia canis activities of nine essential oils were investigated. Among the tested essential oils Achillea millefolium, Eugenia caryophyllus and Citrus grandis were the most active (IC50 values of 51.0, 60.3 and 61.3 μg/mL, respectively). The oils from Abies sibirica, Rosmarinus officinalis, Eucalyptus globulus, Cinnamonum zeylanicum, Mentha piperita and Pinus sylvestris were less active (IC50 values of 134.3, 237.3, 239.3, 367.9, 837.5 and 907.3 μg/mL, respectively). The results support the concept that some essential oil constituents may be useful in the clinical management of babesiosis.