The issue of terrorism has cost Nigeria as a nation a lot and is calling for serious attention; such that insistent attacks on the Nigerian populace by terrorist groups are threatening the security of the country, among others. Hence, this study attempts to explore the viewpoints of employees of NGOs on the social issues that have fueled the increase and effects of terrorism in Nigeria as well as the possible consequences the findings have regarding international social work in Nigerian local communities. The Qualitative research method was used, which involved the use of in-depth interviews for data collection, and the relative deprivation theory served as the theoretical base for the data analysis. It was revealed from the findings that social issues like unemployment, poverty, illiteracy, corruption, religious extremism, and ethnicity problems, among others, could be attributed to terrorism increase; while poverty, internal displacement, and high rate of citizen deaths were some of its main effects in Nigeria. Furthermore, the study indicated that there is an urgent need for the competency of international social workers to combat the root causes of terrorism and its calamitous impacts in Nigeria. However, the study recommends that international social workers who intend to work in Nigeria must collaborate with the Nigerian government or its agencies and understand and learn about the social and cultural intricacies of working in Nigeria for effective practice.