["Australian Journal of Agricultural and Resource Economics, EarlyView. ", "\nABSTRACT\nUnderstanding the determinants of illegal rhino horn prices can provide information for the design of policies to conserve wild rhinoceroses. Using a theoretical model, we identify empirical measures that may affect illegal rhino horn prices and derive testable hypotheses about their expected effects. We test these hypotheses using time series data on actual illegal market prices of rhino horn in Vietnam. The price data were collected from consumers who purchased rhino horn in Vietnam between 2001 and 2020. Assuming that the illegal rhino horn markets in China and Vietnam are perfectly integrated, we examine the effects of various regulatory measures implemented in both countries. We find that China's legalisation of trade in rhino horn antiques and the implementation of an anti‐corruption campaign are associated with significant reductions in illegal rhino horn price in Vietnam, whereas Vietnam's increased sanctions on the rhino horn trade and use have no significant effects. These findings suggest that, in addition to wildlife‐specific policies, broader institutional reforms and governance crackdowns in China may substantially affect illegal rhino horn prices in Vietnam.\n"]