The necessity for thoracoscopy became apparent with the adhesions that limited the success of Forlanini's introduction in 1882 of artificial pneumothorax in the treatment of pulmonary tuberculosis. The first thoracoscopy, using a modified cystoscope, was performed by H. C. Jacobaeus, a professor of medicine, not surgery, in Stockholm, publishing in 1910. Thoracoscopy and division of adhesions (intrapleural pneumonolysis) then spread all over the world, with reports of series of 1,000 or more cases in spite of a significant incidence of complications. Its use declined rapidly after the introduction of streptomycin in 1945, becoming then confined to relatively minor diagnostic procedures except in a few European centers. The advent of video-assisted thoracoscopes and the development of ancillary instruments has allowed a new explosion of thoracoscopic surgery. Surgeons, in whose hands the procedure now rests, should nevertheless be aware of the five unacceptable thoracoscopic disasters--wrong side, kebab lung, "clotted hemothorax," artificial lunchothorax, and aorto-pleuro-cutaneous fistula.