A goat pleuropneumonia outbreak occurring in a herd of 800 animals in the province of Ciudad Real, Spain, is described in this paper. Severe respiratory signs and high mortality were the most significant clinical observations. The adult goats presented mainly respiratory symptoms and/or mastitis, whereas the young animals died showing arthritis and/or keratoconjunctivitis. The most significant lesions were found in the thoracic cavity. A focal extensive fibrinonecrotic pleuropneumonia was macroscopically seen, and the histopathological analysis confirmed a fibrinopurulent and necrotic pleuropneumonia with areas of acute pyogenic bronchopneumonia and fibrinous pericarditis associated with a multifocal purulent mastitis and/or a fibrinopurulent arthritis in some goats. Microbiologically, the mycoplasmas isolated grew rapidly (18-24 h), and, after 48 h, there were colonies of 1-1.5 mm diameter. These isolations were biochemically characterized as Mycoplasma mycoides spp. and showed serological characteristics corresponding to Mycoplasma mycoides subsp. mycoides Large Colony. One of the isolations, the strain 2/93, experimentally showed its pathogenicity causing acute interstitial pneumonia and arthritis when it was inoculated in 1-week-old kids.