Fifty one patients with alveolitis of different genesis (idiopathic fibrotic alveolitis (IFA) in 15, extrinsic allergic alveolitis (EAA) in 20, fibrotic alveolitis (FA) in 10, and eosinophilic pneumonias (EP) in 6), receiving multimodality therapy had a session of plasmapheresis (PA) including 3-4 procedures at a week interval. The session was repeated in 4 patients. The earliest results in all patients appeared as better well-being, improved parameters of blood and external respiratory function and half the patients had positive X-ray changes. The best results were achieved by patients with EP, the worst by those with IFA. Following 2 years, remission retained in a third of patients, recrudescence was noted in two thirds. Five patients with IFA and EAA died. In most patients PA was started late when they had developed recrudescence and respiratory failure. Ineffective therapy made the authors think of PA. The latter improved all the patients' condition and yielded early positive changes in many parameters. PA may have a positive impact in the late period.