Farmers-herders conflict is another dimension of insecurity, as well as socioeconomic and political problem in Nigeria for many decades. The conflict has been in existence for many years but, it has manifested more in recent years especially from 2001 to 2018. One of the problems is the way in which the conflict is affecting nation building in addition to economic problems and security issues. This work is an investigation of the nature of the farmers-herders conflict, causes, manifestations and its effects on nation building as a contribution to intellectual discourse in the area of development studies. The work relied on descriptive qualitative research in data collection and analysis. Secondary sources such as books, journals, reports and internet sources were consulted for data collection. The data obtained were discussed using content analysis where the existing literature were interpreted for further creation of meanings and contribution. The research discovered that farmers-herders conflict has many implications on nation building including insecurity, food security, ethnicity, politicisation of national interest, creation of national disunity, economic sabotage and mutual suspicion among many others. The research as part of its contribution to the discourse discovered that the conflict compounded the Nigerian insecurity through the fueling of banditry in other parts of the country. The research recommends that for a plausible solution towards addressing the issue of farmers-herders conflict in Nigeria, there is a need for sound agricultural, economic and social policies that will target both the farmers and herders to ameliorate their sufferings and this can be done through improved modernisation of farming and livestock rearing.