The changing trend of national and international threats to national security is occasioned by the evolution and development of new factors in the internal and external environment of the Nigerian state. The security of the Nigerian state is aimed at protecting the national integrity of the state and defending the essential values that constitute Nigerian identity. Nigeria is rated high in the regional debate for the control of small arms and light weapons and illegal trade. For more than a decade, diplomatic activity to contain arms and ammunition transfers has been animated by a concern with instability and crises generated in the continent many years back. Leading think tanks, research groups, and advocacy organizations have repeatedly drawn attention to the way the burden of armed violence in Northern Nigeria is a product of high porous borders and low-tech assault by the Nigerian government. The methodology was based on the use of secondary data. The secondary data were collected from textbooks, journals, magazines, periodicals, internet, etc. We started by dwelling on the entire technicality where we posed four research questions, stated four specific objectives, and four research hypotheses. We, also, demonstrated the theoretical and empirical relevance or justifications of this study. We also reviewed the related extent and relevant literature concerning causes, sources, transits and destinations of SALW and problems and consequences of SALW in Nigeria. We further discussed the history of proliferation of SALW in Nigeria, and the Nigerian state and proliferation of SALW in the Northern Nigeria. Whilst, we examined the supply factors and causes of proliferation of SALW, and the law enforcement agencies, SALW proliferation and security situations in the Northern Nigeria. Lastly, effort was made to summarize the entire work and drew some conclusions on the basis of which we made some recommendations. From the foregoing, we reached the following conclusions that: the inability of the Nigerian state to deal with the demand factors heightened the proliferation of SALW in the Northern part of Nigeria. The inability of the law enforcement agencies to check the supply factors of SALW worsened security situations in the Northern part of Nigeria. Reconstitute the Nigerian state in such a way as to be pro-active in dealing with the demand factors of SALW that heightens the proliferation of SALW. Strengthen the law enforcement agencies in order to enable them check the supply factors of SALW that worsens security situations in the Northern part of Nigeria. Thus the thrust of this paper is to look at the Nigerian state and the proliferation small arm and light weapons in the northern part of Nigeria. DOI: 10.5901/jesr.2014.v4n1p415