Pleurotus eryngii, a type of edible mushroom that exhibit various pharmacological properties, including antioxidant and anticancer effects. In the present study, extracted β-glucan from the P. eryngii was tested as an antioxidant and anti-tumor factor. β-glucan was extracted and analyzed by HPLC and FT-IR. Analytical results showed more than 90% similarity in chemical structure and purity. Potential antioxidant activity of β-glucan was examined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and compared with ascorbic acid. β-glucan confirmed a potential scavenging activity. The anticancer activity of the β-glucan was assessed using different concentrations (6.25 to 400 µg mL -1 ) on MCF-7 and HepG2 cell lines. P. eryngii β-glucan exerted a dose-dependent reduction in MCF-7 and HepG2 cell viability with an IC 50 of 280.00 and 539.5 µg mL -1 , respectively. At the same time, no significant effect was recorded on normal cell line WRL 68. The obtained results are expected that could be used to develop P. eryngii β-glucan as an antitumor drug.