Abstract Aim To explore the views of experts within the fields of pharmacy and addiction on the value of current strategies and possible alternatives and to reach an agreement on best practice in the sale of over-the-counter (OTC) medicines which are liable to misuse. Design Using a modified Delphi approach, an anonymous, international, three-stage, postal questionnaire was conducted that generated both qualitative and quantitative data. Participants Of those contacted by telephone (164) from the United Kingdom, Australia, Canada, New Zealand and United States, 109 experts (66%) agreed to take part. Forty-three per cent (47/109) completed all three stages of the study. Measurements A Delphi technique was employed to gather data. The second and final questionnaires were constructed from the responses to the preceding questionnaires. Content analysis of the qualitative data was carried out at each stage. Statistical analyses of the influence of demographic factors, degree of shift in overall opinion between the first and second stages and degree of agreement between respondents at each stage were also conducted. Findings A consensus was reached on the strategies considered the most important and effective. Key areas include improving access to current information, improved staff training, addressing the issues of non-pharmacy outlets and Internet pharmacy sites. Concerns were expressed regarding the possible conflict between commercial and customer interests. Conclusions The consensus view presented offers practical and realistic guidance for policy-makers and community pharmacists on the sale of OTC products. It reflects the best evidence to date of expert views in this area and accords with current UK guidelines. The effective implementation of these strategies can only be achieved with improved communication and coordination at local and national level.