OBJECTIVES:  International reference pricing (IRP) is used by countries to benchmark prices, in order to minimize drug prices. Reference countries can make or break a drug’s launch, and are thus very influential on pricing worldwide. This study will seek to categorize and analyze countries across three metrics to establish levels of and reasons for IRP influence, to assist the drug industry to better launch drugs. METHODS: Reference baskets worldwide were examined for inclusion of 55 of the largest pharmaceutical markets in the world. The 55 countries were then analyzed for degree of influence (how often they appear in reference baskets) and range of influence (how many different geographic regions they are referenced in). The countries were then segmented into levels of influence – top influencers (influential in range and degree), moderate influencers (influential in range or degree) and low influencers. The countries were then examined for a third metric (market size) and for similarities, in order to determine which factors (health technology assessment, cost-containment strategies, demographics, geography, economy, etc.) are common to which segments. RESULTS:  Of the 55 nations examined, 3 were top influencers (influential in range and degree), 28 moderately influential (only 5 in terms of range, 23 in terms of degree) and the remaining were deemed not influential. High influencers, and moderate influencers to a lesser extent, tend to be regional powers, relatively wealthier, have strong health technology assessment (HTA) structures and employ many cost-containment strategies. Uninfluential nations tend to not use HTA or have high costs, free pricing or unusual demographics. CONCLUSIONS:  The four resulting segments feature distinct profiles that affect international reference pricing, with many similarities between the countries in each group. Through the use of this influence-ranking system, the drug industry can understand which nations are influential in what contexts, and develop a strategy for successfully launching new drugs.