OBJECTIVES: Pharmacovigilance as a part of drug safety surveillance consists in collecting and analysing adverse effects reports and is intended to evaluate the safety of medicinal products and to eliminate drugs whose risks outweigh therapeutic benefits. The research  aims were: to recognize the rules of current pharmacovigilance practices, to examine their capacity to effectively manage public health and to propose an improved pharmacovigilance model. METHODS: The rules of drug safety monitoring in the United States, Canada, the UK and Poland have been presented, analysed and compared. In order to assess the effectiveness of the respective national practices, an additional analysis covered reports prepared by healthcare professionals, consumers and MAHs, submitted to the responsible healthcare agencies (FDA, Health Canada, MHRA and URPL, WMiPB). Based on the results, an improved pharmacovigilance model was proposed. A case study of VIOXX® was used to review different pharmacovigilance practices by analysing reports on this recalled drug, including the incidence and type of adverse effects reported, principles of pharmacovigilance signal detection and measures, taken by the agencies. The model was then subject to final evaluation. RESULTS: The analysed pharmacovigilance practices allowed to collect sufficient data on adverse effects, but none of the agencies raised any alarm addressing safety issues before the product was recalled by the manufacturer. CONCLUSIONS: The procedures underlying pharmacovigilance practices need to be amended by adopting the ideas proposed in the model, especially in the area of data analysis and signal detection, for instance: rigorous five-year safety monitoring of new products, especially post-marketing surveillance; publicly available adverse effects reports collected by the agencies; publicly available standards of signal detection based on MAHs declarations in SPCs; and including clinical trials’ analysis in  standard drug safety monitoring.