This study investigates the impact of the flight departure tax introduced in Sweden 1st of April 2018. The study focuses on how the departure tax has affected the numbersof flight passengers with domestic and international destinations. The analysis covers the time the period 2010-2019. A Difference-in-Difference approach and a dynamic Difference-in-Difference approach was used in this study. The results indicate that theflight tax reduced the numbers of passengers traveling both domestically and internationally in short term. Furthermore the estimations show that the tax had its largest effectduring the second year compared to the first year when the tax was introduced. However the effect seems to reduce in the last quartile of 2019 prominently among domestic travelers. The study suggests that further reaserch should be done in the field with moredetailed data of how the different tax rates in the swedish depature tax affected thenumbers of passengers covered by those tax rates. Subsequently a further research on how the tax affected the cross price elasticity between passengers traveling by train andairplane is suggested.