More than 40 years ago British and German neurosurgeons met in Berlin and Breslau to exchange their experiences, to strengthen their friendly bonds, and to enjoy the attractions of both cities and their surroundings. In 1960 a joint meeting of the Dutch and German societies took place in Rotterdam by invitation of the Nederlandse Vereniging van Neurochirurgen. All who attended this meeting thankfully remember the great hospitality during these unforgettable days. In 1970, by courtesy of the Society of British Neurological Surgeons, German neurosurgeons had the pleasure to become acquainted with the great tradition of British sciences at one of the most famous places during the meeting in Cambridge. These impressions were deepened by visits to other famous sources of British scientific tradition during the European Congress in Oxford in 1975. The critical distance sometimes necessary towards our own discipline is implicit in the major themes of this meeting. Complications following shunting procedures for hydrocephalus have been discussed on the basis of the results of a cooperative study of some German neurosurgical departments. The second main topic was problems and diagnostic errors in computer tomography. The papers presented contain critical considerations about the findings obtained by this method, as well as on its possibilities and limitations. German neurosurgeons felt deeply indebted to their British and Dutch colleagues and wanted to return their kindness at this joint meeting in Berlin. We hope that all participants will retain pleasant memories of the days in this city.