Of cases above mentioned 68 of them underwent surgery. As to the direct operation results, lobectomy and segmental resection were accomplished most often and them came thoracoplasty, pneumonectomy and extrapleural pneumolysis in that order. For those with poor function, thoracoplasty and extrapleural pneumolysis were selected as the procedure of choice. The operative mortality rate was 4.4%. They were because of complications not directly related to functional impairment and could have been avoided by adequate supervision. Complications occurred in 20.4% of the cases, being more frequedcly than in milder cases. Particularly higher was the incidence when the pulmonary arterial mean pressure was above 20 mmHg and other values showed marked fall in function. Complications were observed most often in thoracoplasty, but this can mainly be attributed to the fact that cases of severest functional ruin were chosen for this procedure. The ventilation diminished following every surgical intervention, Generally in thoracoplasty and pneumonectomy a qualitative improvement was noted of ventilation and circulation, whereas in lobectomy and sagmental resection with no addidion of thoracoplasty an aggravation was noticed. This concerns, however, with the indication preceeing operation and does not help estimate the absolute value of each surgicai procedure. It is suggestive of the possibility that the pulmcnary function of patients with far advanced pulmonary tuberculosis can be improved by deliberate choice of indication and surgical procedure.