Chenopodium species have been used in folk medicine and as vegetable for years. In the present study, the total phenolic and flavonoid contents, biological activities, phenolic constituents and fatty acid profile of Chenopodium album subsp. album var. microphyllum (Boen.) Aellen were determined for the first time. The antioxidant effects were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and cupric ion reducing antioxidant capacity assays (CUPRAC). The Ellman method was applied for the determination of the cholinesterase inhibition activity. The phenolic constituents of the methanol extract and the fatty acid profile of the n-hexane extract were evaluated by LC-MS/MS and GC-MS, respectively. Acetone and methanol extracts showed similar DPPH free radical scavenging activities (0.68 +/- 0.07 and 0.68 +/- 0.05 mmol Trolox/g extract, respectively), whereas the cupric ion reducing capacity of the acetone extract was the highest (0.41 +/- 0.05 mmol Trolox/g extract). Acetone and methanol extracts had moderate butyrylcholinesterase inhibitory activities as 65.29 +/- 1.56% and 52.64 +/- 2.78%, respectively, whereas non of the extracts possessed anti-acetylcholinesterase effect. The methanol extract was found to contain significant amounts of hesperidin (9769.13 +/- 158.26 mu g/g extract) and rutin (2935.19 +/- 39.92 mu g/g extract). The major fatty acid constituents of the n-hexane extract were identified as myristic acid (18.26%) and cis-10-pentadecanoic acid (15.39%).