In pharmacoeconomic research sponsored by companies, there is an obvious tension between the desire to undertake studies to show a marketing advantage and the desire to adhere to good scientific principles. This tension was explored in an early issue of PharmacoEconomics and is now revisited 5 years on. Bias is still perceived to be a major problem in industry-sponsored studies, both by healthcare decision-makers and journal editors. However, the debate about bias has matured over the years. Also, actual evidence of bias in study methodology is sparse, although biases in study topic selection and in the use, in promotion, of study results have been found. A number of constructive suggestions have been made in the last 5 years for reducing potential bias. These include developing methodological guidelines and standards, improving the peer review process, clarifying contractual relationships between sponsors and analysts, and ensuring appropriate use of studies in promotional activities. However, further initiatives could be undertaken. These include additional guidelines for specific detailed areas of economic evaluation methodology, changes in the structure of funding for pharmacoeconomic research, more education of consumers for pharmacoeconomic data and more research partnerships between industry and its customers.