This paper aims to investigate the effect of political instability and terrorism on Tunisian financial market. Estimation of Power ARCH model between 2005 and 2015 provides support for the negative effect of informal political instability (assassinations and revolution), formal political instability (major government crises and a number of major constitutional changes) and terrorism on the Tunisian financial market. Moreover, the results highlight assassination as a source of political risk, as it has more significant and greater effect on stock market returns as compared to other sources of political instability. Thus, this result is very important for government authorities who should create a security system for all people and in particular for the members of the political parties to ensure the stability and performance of the Tunisian financial market.