Extracorporeal shock wave therapy (ESWT) is simply evolved from extracorporeal shock wave lithotripsy known as a revolutionary non-invasive technique for treating kidney stone diseases. Since ESWT was approved for treating plantar fasciitis by FDA in 2000, it has been rapidly accepted into various clinical practices. Its indication includes chronic tendinitis and pseudoarthrosis, and has been widened to various applications other than orthopeadics. Little has been reported on their acoustic properties, yet, even if a number of clinical ESWT systems are readily available. This article reviews the acoustical aspects of ESWT and discusses critical issues towards acoustic exposure optimization and shock wave dosimetry.