Abstract: Religious fundamentalism in the South Asian region has assumed serious proportions in the last few decades. Sri Lanka, India Pakistan and to some extent Bangladesh face this problem. It is therefore necessary to examine this problem in detail.The question that crops up is what is religious fundamentalism? Why does it get aggravated so as to express itself violently. At the same time the difference between ethnicity and religious fundamentalism too should be clarified. Thus we first come to the issue of ethnicity. Ethnicity, anthropologists and Sociologists maintain, is a feeling of primordial identity with one’s social religious, linguistic or cultural group.