Terrorism has been considered as a challenge with serious effect in the world as a result of instability, corruption and lack of democracy in most countries. Confronting this phenomenon requires recognizing its roots to find possible solutions. This study aims to examine the effect of some actual factors which causes the terrorism in short and long run. To this end, investigation has been conducted using statistical and regression methods using the data obtained from the 17 MENA countries. Findings indicate that in the long run, political stability and corruption controlling have a negative effect on the number of terrorist attacks, but democracy has no significant effect on terrorism. Morover, in the short term, there is also an inverse relationship between the number of terrorist attacks with political stability and corruption controlling, but unfortunately, democracy has a positive and significant effect on the number of terrorist attacks in the selected countries.