The antioxidant activities of Phellinus igniarius (PI) and Ganoderma lucidum (GL) extracts were evaluated after far-infrared (FIR) irradiation. PI and GL were irradiated at $120^{circ}C$ for 30, 60, 90 and 120 min with a FIR heater (2-14 ${mu}m$), and then extracted by distilled water for 1 hr. Total sugar contents (TSC), total phenolic contents (TPC), radical scavenging ability (RSA), and reducing power (RP) were significantly increased by FIR irradiation. When PI was irradiated for 120 min, the TSC, TPC, RSA, and RP values of the PI extracts increased from 10.1 to 25.9 mg/g, 6.1 to 13.4 mg/g, 23.8 to 51.5%, and 0.222 to 0.363, respectively, compared to the untreated controls. The GL extracts, under the same conditions ($120^{circ}C$ for 120 min), also increased in TSC, TPC, RSA, and RP from 11.1 to 22.6 mg/g, 2.5 to 5.8 mg/g, 14.5 to 18.6%, and 0.271 to 0.296, respectively. These results indicate that appropriate FIR irradiation of PI and GL could enhance the antioxidant activities of their extracts by increasing amounts of phenolic and sugar compounds.