Trichomonas vaginalis (T. vaginalis) is a parasitic protozoan that causes trichomoniasis. Metronidazole is the standard treatment for trichomoniasis; however, metronidazole-resistant strains are implicated in an increasing number of refractory cases. Therefore, the discovery of an antiprotozoal agent that is effective on metronidazole-resistant T. vaginalis will prevent major health problems. In this study, we investigated the antiprotozoal effects of leaf, fruit and body extracts of Viscum album L. ssp. austriacum (VA) on metronidazole-resistant and - sensitive T. vaginalis protozoa. The VA used in our study was collected from 20 different pine trees in September and October. The leaves, fruits and bodies of the VA plants collected were separated and dry extracts were obtained with hexane, chloroform, n-butanol, ethyl acetate and water. The minimum lethal dose (MLD) of the metronidazole-sensitive strain, T. vaginalis ATCC50148 and themetronidazole-resistant strain, T. vaginalis ATCC50143 against metronidazole was tested in comparison with the plant extracts. In addition, GC-MS analysis was performed on the plant extracts that has antiprotozoal effects. Some of the substances identified from GC-MS analysis were purchased commercially and their antiprotozoal effects were further investigated. The VA leaf and fruit ethyl acetate extracts and body butanol extract had the most effect on T. vaginalis. GC-MS qualitative analysis detected 2,4-heptadienal, 3-methylsilane, and 2-methylfuran. Of these substances, only 2-methylfuran was found to be effective on T. vaginalis strains. Our findings suggest that the 2-methylfuran found in Viscum album L. ssp. austriacum extracts may be an alternative chemotherapeutic agent to metronidazole. (C) 2019 SAAB. Published by Elsevier B.V. All rights reserved.