Tourism is a multidimensional economic activity that has an interaction with the environment. On one hand, environmental resources provide the raw material for tourism, while on the other, tourism imposes a variety of negative and positive impacts (wanted or unwanted) on the environment through the creation of various by-products. The main purpose of the current study is to investigate the relationship between tourism and environmental performance in the Caspian Sea nations during 2002-2013. A panel data vector autoregressive (P-VAR) method has been employed to estimate the model. Findings from the impulseresponse function analysis and variance decomposition show that the reactions of international tourism to environmental performance, human development index, gross domestic product (GDP) per capita, and the degree of trade openness in the Caspian Sea nations are positive. Moreover, the reaction of environmental performance to tourism and GDP per capita shocks is negative. The results also show that the responses of environmental performance to human capital index, the degree of trade openness and the square of GDP per capita shocks are positive. According to the findings, it is suggested that countries in the Caspian Sea region should pay a special attention to environmental issues in the development of tourism.