Since apheresis may be performed in many different ways for many different indications world wide the World Apheresis Association (WAA) decided to start a registry. The aim of the registry is to improve knowledge about indications, techniques and adverse events to optimize information and therapy of the patients. In addition the knowledge will be helpful for industry to further develop devices and bring them into market. In December 2002, WAA launched such world-wide apheresis registry to gain insight into the extent of treatment, adverse events, and to facilitate contacts among centers when treatment indications are rare and experience limited. Apheresis procedures to collect stem cells and other blood products, intended for clinical application, should also be able to enter. Since then several centers and countries have entered the registration procedure. Each centre at the end of the year gets a file of their own data for own statistics. We now cordially invite also other centers to join the registry. Please, also inform colleagues at other centers in your country to join. E-mail and address lists of colleagues in your country who have not registered will be welcomed. The site is available at: Go to World Apheresis Registry; Login code to test the Registry is: al61tms (AL61TMS). Then apply for a specific login code for your center. We welcome you to this registry for your input of data. You will not be charged any registration fee. At the moment the site is also under development to facilitate registrations and feed back. In the future the registry is planned to include information about indications, techniques and various interactive approaches.