This report presents the recommendations of an international group of experts convened by the World Health Organization to consider matters concerning the quality assurance of pharmaceuticals and specifications for drug substances and dosage forms. Of particular relevance to drug regulatory authorities and pharmaceutical manufacturers, the report discusses activities related to the development of The International Pharmacopoeia and basic tests for pharmaceutical substances and dosage forms, as well as quality control of reference materials, good manufacturing practices (GMP), stability studies, inspection, hazard analysis, procurement, storage and other aspects of quality assurance of pharmaceuticals, and regulatory issues. The report is complemented by a number of annexes, including recommendations on the risk of transmitting animal spongiform encephalopathy agents via medicinal products, guidelines on GMP for pharmaceutical products, a model certificate for GMP and guidance on a GMP inspection report. The final annexes provide guidance on the application of Hazard Analysis and Critical Control Point (HACCP) method to pharmaceuticals, good storage practices and a procedure for assessing acceptability of pharmaceutical products for purchase by United Nations agencies.