Conditional release is the approval of a new drug onto the market, subject to specific conditions relating to effectiveness and safety that, if achieved, will lead to full approval. Conditional approval of a new drug, during which time it is used in normal clinical practice, should allow the collection of data on effectiveness and safety to provide a genuine cost effectiveness evaluation. Proposals put forward in 1977 in the United Kingdom for approving a drug on a conditional basis while monitoring for adverse drug reactions are examined, and issues that would affect a present day conditional release scheme are identified. These issues are: who would do the evaluation and who would pay for it; how would patients be identified and registered; would all new drugs be monitored and for how long; what data would be reported and evaluated; and who would do the reporting' How a conditional release scheme would work in Canada in light of these questions is considered and a method based on pharmacists registering patients and on physicians and/or patients reporting data to an independent organization funded by governments and the pharmaceutical industry is outlined. Under certain conditions, conditional release would provide the information to allow true cost effectiveness and safety assessments instead of the current inadequate predictions based on efficacy and safety data from clinical trials. It is important that academics and drug approval and monitoring agencies work together to develop active systems to improve the postapproval evaluation of effectiveness, safety and cost effectiveness of new drugs in Canada.