The phenolic and essential oil profiles and, antioxidant and anticholinesterase activities (AChE and BChE inhibitory activities) of Origanum amanum Post endemic to Turkey were investigated. The oil was obtained by applying hydrodistillation method and analyzed by GC-MS/MS. The plant was extracted with chloroform (C), acetone (Ac) and methanol (M). The extracts were analyzed through LC-MS/MS and the phenolic compounds were determined in quantitative amounts. Inhibition of lipid peroxidation, Cu2+ and DPPH scavenging and anticholinesterase activity of the extracts were analyzed. The main compounds of the essential oil of O. amanum were determined as cymene, carvacrol and gamma-terpinene. Rosmarinic, t-ferulic and caffeic acids were determined as the main compounds of the extracts. While the extracts did not inhibit AChE, Ac extract inhibited BChE moderately. Moreover, acetone and methanol extracts of O. amanum showed good antioxidant activity.