Evaluating anti-oxidant potential of Ganoderic acid A in STAT 3 pathway in Prostate cancer. Molecular docking and ADMET activities of different isoforms of ganoderic acid on STAT 3 pathway were performed by Maestro 9.6 (Schr�dinger Inc). The ganoderic acid A is best-docked among isoforms which analyses the expression level of antioxidant and STAT 3 pathway in PC-3 cells. The receptor-based molecular docking reveals the best binding interaction of SH2 domain of STAT3 and ganoderic acid A with GScore (?6.134), kcal/mol, Lipophilic EvdW (?1.83), Electro (?1.1), Glide emodel (?31.857), H bond (1.98), MM-GBSA (?69.555). The molecular docking QikProp analyzed the absorption, distribution, metabolism, excretion, and toxicity (ADME/T). The ganoderic acid A is best-docked among isoforms which downregulates the expression of STAT 3 in PC-3 cells. Moreover, ganoderic acid A inhibits proliferation, viability, ROS, DPPH, and analyzed the expression of SOD1, SOD2, and SOD3 by Real time PCR in a PC-3 cell in a dose-dependent manner. Molecular docking revealed the mechanistic binding of Ganoderic acid A in STAT3 signaling, which inhibits the proliferation, viability, and ROS in PC-3 cells. � 2016, Springer Science+Business Media Dordrecht.