The present study was carried out to investigate and identify bioactive compounds along with antioxidant capacity, total flavonoids and total phenolic contents from two saprophytic <i>Amanita</i> species, i.e., mushrooms <i>A. manicata</i> (Berk. & Broome) Pegler and <i>A. nana</i> Singer. Antioxidant potential was assessed by DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging and ABTS (2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) assay, total phenolics, and flavonoids. Both mushrooms were found to possess antioxidants and wide range of phenolics and bioactive compounds. There was maximum percent inhibition (83.2 ± 0.120%) on DPPH by <i>A. manicata</i>. However, maximum percent inhibition using ABTS was found to be 79.5 ± 0.251% by <i>A. nana</i>. Similarly, <i>A. nana</i> possesses maximum amount of both flavonoids and phenolics i.e., 0.3473 ± 0.0088 mg/100 g of catechin and 0.097 ± 0.0011 mg/100 g of GAE equivalent, respectively. Both mushrooms exhibited a variety of natural compounds such as <i>P</i>-coumaric acid, <i>M</i>-coumaric acid, benzoic acid, ferulic acid etc. Ferulic acid, chlorogenic acid, and cinnamic acid were also detected in <i>A. manicata. A. manicata</i> exhibited best and greater antiradical potential than <i>A. nana</i> due the presence of excessive natural bioactive compounds. From the reported results, it was revealed that both inedible mushrooms could be a potential source of antioxidants and secondary metabolites and might be used for making novel drugs in future by pharmaceutical industries.