This paper explores potential ways to develop experimental estimates of the value of U.S. imports of illegal drugs. It builds on the initial exploration of this topic by the Bureau of Economic Analysis (BEA) in Soloveichik (2019), which presents experimental estimates of U.S. domestic consumption of illegal drugs and of import of illegal drugs into the United States. In this paper, I extend Soloveichik’s research by exploring the feasibility of developing estimates of imports of methamphetamines and marijuana using seizure data, and I evaluate the extent to which source data allow us to estimate heroin and cocaine imports by geography. International guidelines for national economic accounts (the System of National Accounts 2008, or SNA) and international economic accounts (the Balance of Payments and International Investment Position Manual, sixth edition) explicitly recommend that some illegal market activity should be included in measured output. Soloveichik suggests that illegal drugs comprise the largest share of imports of this activity for the United States and would have added $111 billion to U.S. GDP in 2017.