Macrocybe crassa, a wild mushroom growing mainly in coastal areas of West Bengal, has been widely used as food for its flavour and taste. The present study was conducted to emphasize on antioxidant and antimicrobial activity as well as phenolic profile of crude ethanolic extract of this mushroom (EfraMac). Mycochemical analysis showed presence of bioactive components in the following order: phenol> flavonoid> ascorbic acid> β-carotene> lycopene. Further analysis with HPLC revealed that the dominant phenolic in EfraMac was pyrogallol, whereas vanillic acid, cinnamic acid and p-coumaric acid were present in less amounts. Antioxidant activity was determined by using superoxide radical scavenging, DPPH. radical inhibition, chelating ability of ferrous ion and total antioxidant activity assays. Promising results were obtained as evident by low EC50 values (ranging from 0.53 mg/ml to 1.66 mg/ml) and high ascorbic acid equivalent antioxidant capacity data. In addition, EfraMac exhibited antimicrobial effect against three Gram positive (Listeria monocytogenes, Staphylococcus aureus, Bacillus subtilis) and two Gram negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, whereas Salmonella typhimurium was resistant to the fraction. Overall results indicated that the mushroom can serve as a good source of polyphenols in the human diet due to high concentrations of total phenolic compounds as well as their strong bioactivity. Moreover, the present study reports antioxidant and antimicrobial activity in relation with phenolic profile of Macrocybe crassa for the first time. © 2014, Global Research Online. All rights reserved.