In this study, Allium tuncelianum, one of the endemic garlic species growing in Anatolia, was investigated for its phytochemical content. LC-MS/MS, HPLC, GC-MS, GC-FID and ICP-OES techniques were used for this purpose. Major phenolic components of Allium tuncelianum were found to be malic acid (3322.6 mu g/g), kainic acid (626.8 mu g/g), cinnamic acid (69.15 mu g/g), fumaric acid (13.02 mu g/g) and catechin (3933.3 mu g/g). The main components of volatile oil, on the other hand, were detected as diallyl disulfide (28.30%), diallyl trisulfide (30.90%) and allyl methyl trisulfide (9.44%). The fatty acid composition of the plant was revealed as oleic acid (27.19%), linoleic acid (19.46%) and elaidic acid (3%) whereas high content of potassium (4207 +/- 67 mg/kg), calcium (518 +/- 35 mg/kg) and magnesium (376 +/- 20 mg/kg) was determined as the minerals. Moreover, cytotoxic effects of ethanol/water and hexane/chloroform extracts of the plant were evaluated in prostate, colon, cervical and breast cancer cell lines and cytotoxicity of both extracts were detected for all the cell lines studied. Therefore, we conclude that Allium tuncelianum may be a new phytotherapy agent with its rich phytochemical content and anticancer activity.