The rapid increase in medical knowledge and the introduction of new diagnostic and therapeutic techniques has also led to increasing specialisation in the field of internal medicine. For this reason controversy has arisen, particularly in university centres, about the importance and role of "general" internal medicine compared to the medical specialties. In this paper the most important tasks of internal medicine in patient care, in graduate and postgraduate training and in clinical research are analysed. The prime task of internal medicine is comprehensive care for the increasing number of elderly patients with multiple co-existing diseases. In this respect generalists cannot be adequately replaced by specialists. Mutual critical co-operation between internists and specialists also reduces the risk of overuse of medical technology and leads to a corresponding reduction in hospital costs. In medical schools internists have a major task in teaching bedside clinical examination and a general approach in the diagnosis and treatment of the most relevant medical disorders, while specialised knowledge becomes more important during the postgraduate training period. Hospital-based internal medicine remains an essential basis for clinical training not only for general internists and family physicians but also for all medical sub-specialties. In continuous medical education internists have the task of synthesising and transmitting new knowledge from the various special fields, including their application in a non-selected broad patient population. Also in clinical research several tasks remain for internists, such as clinical epidemiology, cost-benefit analysis and critical evidence-based assessment of diagnostic and therapeutic methods. Discontinuance or drastic reduction of internal medicine in university centres would not be justified and could lead to a negative balance between general internists and specialists, with negative consequences for health care, as experienced in the USA. Instead of fragmentation and rivalry for positions and resources, better co-ordination and co-operation between internists and specialists is needed in university centres, if possible in integrated medical departments.