Book excerpt: Swine can be infected with many different mycoplasmas. Some are important pathogens, causing significant health and welfare issues in pigs and major losses to the swine industry worldwide. Other mycoplasmas are not pathogenic for swine and can be considered commensals. This book provides up-to-date scientific, clinical and practical information of the most important pathogenic mycoplasmas in swine. Most emphasis has been placed on Mycoplasma hyopneumoniae as the most economically important, but other pathogenic species like Mycoplasma hyorhinis, Mycoplasma hyosynoviae and Mycoplasma suis are also discussed. Written by internationally renowned scientists and clinicians from all over the world, this book draws together in depth knowledge, expertise and experience in swine mycoplasmas to provide an evidence-based, academically rigorous and practical collection. It aims to serve the scientific and veterinary community and the swine industry worldwide.