Large intracranial tumours (diameter > 4.5 cm) invading skull base are not frequent. In Department of Neurosurgery in Poznań 22 patients were operated on between 1977-1966. There were 15 males and 7 females. Mean age was 34.78 +/- 15.31 years. The authors analyse the time between the onset of illness and diagnosis, symptoms and neurological condition. Tumour localization was verified by X-rays, computed tomography, cerebral angiography and in some cases magnetic resonance. There were 11 tumours in both fossae--anterior and middle, in 7 tumour site was limited to anterior and in 4--to middle fossa. Extracranial tumour penetration was observed as follows: in 10 cases into paranasal sinuses, 10--orbit, 8--nasopharyngeal cavity and in 4 cases into subtemporal fossa. The authors discuss surgical methods, histological appearances and postoperative complications. Mortality rate was 9% (2 patients died).