The monitoring of adverse drug reactions (ADRs) has a history of more than 25 years in Poland. Its desirability was not well perceived for many years due to the availability of primarily old/generic drugs on the market. With economic changes in the period of 1990–1996 some 6,000 new preparations were registered and put on the market. This large number of new drugs/chemical entities along with other homeopathic and herbal products made it necessary to revitalize ADR monitoring. The new Pharmaceutical Act of 1991 introduced the obligation for marketing authorization holders to monitor and report ADRs to a regulatory authority. Detailed guidelines on company reporting followed. To improve the work and efficiency of spontaneous reporting, efforts were undertaken to restructure the central national system into a regional organization based on the French experience. Also, a number of educational and promotional activities were undertaken such as training courses, lectures, publications, and so forth. A new reporting form and the Drug Bulletin (as a source of relevant information) were introduced. Other activities preceded those specified in the World Health Organization (WHO) Guideline for Establishing and Functioning of Pharmacovigilance Centers drafted in 1996. The current organization, everyday work, and background to national and international cooperation on ADR monitoring is also presented.