Antimycin A is widely used as a piscicide in the catfish farming industry (brandname Fintrol) and has potent killing activity against insects, nematodes and fungi. Antimycin A is a potent inhibitor of ubiquinol-cytochrome C oxidoreductase (complex III). By inhibiting cytochrome C reductase in the electron transport chain of mitochondria antimycin A halts respiration. It has been used to study the metabolic signature of RCD in human cultured skeletal muscle cells. The specific sites of reactive oxygen species (ROS) production in mitochondria isolated from skeletal muscle of chronic obstructive pulmonary disease and lung cancer patients, and its relationship with local oxidative stress induced by exercise have been studied using antimycin A as well. More recently, antimycin A has attracted attention as a potent and selective inhibitor of the mitochondrial anti-apoptotic proteins Bcl-2 and Bcl-xL which are over-produced in cancer cells resistant to apoptosis-inducing chemotherapy agents, so antimycin A may have a potential as anticancer drug for combination chemotherapy.