Four methods used for obtaining information from patients on adverse drug reactions are reviewed on the basis of personal experience. In the development of new therapeutic drugs the method which records all events experienced by a patient during drug treatment is to be preferred as it increases the possibility of detecting unanticipated or previously unreported adverse reactions. Disadvantage of this method is that a high number of events not related to drug treatment may be recorded, causing problems in analysis of the data. © 1990 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.