OBJECTIVES: International drug price comparisons rank countries according to the price of the available drugs. The results of these studies are often used as economic indicators and as political communication tools. The methodologies often rely on hypothesis built by the authors and involve numerous uncertainties. The main goal of this work is to evaluate the consistency of methodologies used in studies that compare drug prices in OECD countries and to assess to what extent results are reliable. The second objective is to propose a reading grid to evaluate the quality of methodologies used. METHODS: All full-text available studies referenced from Pubmed, Web of Science, Science Direct, Springerlink but also grey literature, published between January 2007 and March 2017 have been analyzed. The research focused on original drug price comparisons made in OECD countries. Comparisons studies involving only generic drugs were excluded. Each article has been analyzed regarding six main criteria: data sources, compared countries, drug selection, price used, economic environment and date of the data used. RESULTS: Thirteen studies have been retrieved. It appeared that 5 studies were based on non-official data sources; 11 studies compared countries with a diversity of socio-economic characteristics; 8 studies didn’t use any economic adjustment to compare drug markets; 9 studies were not explicit about drug selection; 4 studies didn’t use ex-factory prices and 2 studies were realized during a major event in a country that affected pharmaceutical industries. CONCLUSIONS: There is a crucial need for methodological guidelines that international drug price comparisons should follow in order to provide results reflecting actual pharmaceutical economy, especially in the political context surrounding high drug pricesUsing the six main criteria selected, the grid developed can serve as a support for methodology qualifications to estimate the quality of the comparisons and ensure the consistency of drug prices.