Due to the information overload and the unstructured access to (medical) information of the internet, it isn't hardly possible to find problem-relevant medical information in an appropriate time (e.g. during a consultation). The web offers a mixture of web pages, forums, newsgroups and databases. The search for problem-relevant information for a certain knowledge area encounters on two basic problems. On the one hand, you have to find in the jungle of the information, relevant resources for your individual clinical case (treatment, diagnosis, therapeutic option etc..). The second problem consists of being able to judge the quality of individual contents of inteernet pages. On the basis of the different informational needs of health care professionals and patients a catalog with inteernet resources was created to tumor diseases such as lung cancer (small cell and non-small cell carcinoma), colorectal cancer and thyroid cancer. Explicit and implicit metainformation, if available, such as the title of the document, language, date or keywords are stored in the database. The database entries are editorially revised, so that further specific metainformation is available for the information retrieval. Our pragmatic approach of searching, editing, and archiving of internet content is still necessary since most of the web documents are based on HTML, which doesn't allow for structuring (medical) information and assigning metainformation sufficiently. The use of specific metainformation is crucial in order to improve the recall and precision of internet searches. In the future, XML and related technologies (RDF) will meet these requirements.