OBJECTIVE Feline immunodeficiency virus (FIV) causes AIDS-like symptoms in domestic and wild cats. Treatment of infected cats has been performed using human anti-HIV drugs, which showed some limitations. This study aimed to determine the anti-FIV potential of some mushrooms. METHODS A total of 17 medicinal and edible mushrooms were screened to find their inhibitory effect against FIV reverse transcriptase (FIV-RT). Three solvents, water, ethanol, and hexane, were used to prepare crude mushroom extracts. Fluorescence spectroscopy was used to perform relative inhibition and 50% inhibitory concentrations (IC50) studies. RESULTS The ethanol extract from dried fruiting bodies of Inonotus obliquus showed the strongest inhibition with an IC50 value of 0.80±0.16 μg/mL. The hexane extract from dried mycelium of I. obliquus and ethanol and water extracts from fresh fruit bodies of Phellinus igniarius also exhibited strong activities with the IC50 values of 1.22±0.20, 4.33±0.39, and 6.24±1.42 μg/mL, respectively. The ethanol extract from fresh fruiting bodies of Cordyceps sinensis, hexane extracts from dried mycelium of I. obliquus, ethanol extracts of Ganoderma lucidum, hexane extracts of fresh fruiting bodies of Morchella esculenta, and fresh fruiting bodies of C. sinensis showed moderate anti-FIV-RT activities with IC50 values of 29.73±12.39, 49.97±11.86, 65.37±14.14, 77.59±8.31, and 81.41±17.10 μg/mL, respectively. These mushroom extracts show anti-FIV potential. CONCLUSIONS The extracts from I. obliquus, P. igniarius, C. sinensis, and M. esculenta showed potential anti-FIV activity.