This study was carried out to identify medicinal mushrooms with protective effects against oxidative stress in PC12 neuronal cell line, followed by evaluation of their antioxidant property. Extracts of medicinal mushrooms, including Ganoderma lucidum extract (GLE), antler-shaped Ganoderma lingzhi extract (AGLE), Hericium erinaceus extract (HEE), and Sanghuangporus baumii extract (SBE), were screened for cytotoxicity using MTT assay. None of the extracts up to 10 μg/ml concentration affected cell viability. These extracts were further checked for their protective effect against oxidative stress-induced reactive oxygen species (ROS) production. Exposure to 50 μM H2O2 induced ROS generation in PC12 cells, which was inhibited only by treatment with AGLE. In addition, inhibition of H2O2-induced ROS generation by AGLE was found to be in a dose-dependent manner (2.5, 5, and 10 μg/ml). Microscopic examination of DCF fluorescence for detection of ROS showed a similar pattern. Further, antioxidant activity of AGLE was determined by ABTS radical cation assay, and its IC50 was found to be 46.90±0.31 μg/ml. Taken together, these results suggest that AGLE may help to alleviate oxidative stress in PC12 neuronal cells.