After 9/11, Muslims have been raced as extremists and terrorists. Although, extremism is not a religious phenomenon but in the contemporary days it is being considered that the religious mindset is involved in such extremist activities. The violent aspect of extremism is changing the peaceful environment of the world. This book, therefore, provides the different manifestations of extremism, nature, causes, and solutions. As far as Islamic perception is concerned, the root word of Islam is "salaama" means peace. It means the flesh and blood of Islam is peace which comes from moderate and balanced life. Both Allah and His Holly Prophet (SAW) warn those Muslims who are excessive and violent in religious rituals, particularly when they go beyond the moderate Islamic position. Tolerance, moderation, peace, etc. are the major moral teachings of Islam. Terrorism and violence are not the part of Islam. Almost 1400 years have passed but Islam is still the most moderate, accommodating and flexible religion in the entire world. It is therefore, would not be unjust to say that Islam is applicable in the modern age. All we need to look from a new position.