Taxes have great importance among fiscal policy instruments for ensuring economic stability. Developing countries such as Turkey are affected by economic eventsand their tax revenues may fluctuate during periods of economic crises. In this study, the relationship between Turkey’s tax revenues and per capita gross domestic product, informal economy, economic growth and crises by using the least squares method for the period 1988-2016. According to the results obtained, while the relationship between the tax revenues and per capita gross domestic product is observed to be in the same direction, the relationship between tax revenues and informal economy and economic growth variables is found to be in opposite direction. Additionally, the 1990, 1994 and2008 crises are found to have a negative effect on tax revenues. However, no significant effect of the 2001 crisis is found on tax revenues. Our findings suggest that governments need to take measures to increase personal income, adjust tax tariff structures in order to facilitate income flexibility, apply tax reductions, reduce tax losses and evasions, as well asincrease tax awareness and tax morale.