Among tumourous affections of the pleural cavity dominate metastatic processes while primary pleural neoplasms are relatively rare (only 5%). The authors present 4 case-records of less common primary benign pleural tumours which were operated at the Surgical Clinic of the Faculty Hospital in Plzen during 2000. Three women and one man of different age groups were involved. In three patients accidental findings were involved, in one instance in conjunction with multiple injuries, the fourth patient was examined on account of pulmonary complaints. The diagnosis was based on the skiagram and specially on the CT of the lungs, individually also other methods were used. All findings were radically eliminated--twice by thoracotomy, twice using miniinvasive procedures. Histological examination revealed twice desmoidal fibromatosis, once a benign fibrous pleural tumour and once a rare variant of Castleman's disease. The postoperative period was free from major complications, without the need of surgical revision. Two years after surgery all patients are free from detectable signs of relapse. The authors submit at the same time an integrated view on the problem of pleural neoplasias, they discuss in particular the pitfalls of the diagnosis of these lesions, possible treatment, incl. the use of suitable endoscopic methods, and the prognosis of different types of tumours. A more detailed histopathological analysis of the described findings is given.