This study examined the reasons for inter-agency grudge among the uniforms in Nigeria with particular reference to the Nigerian police-military clashes in post-independence Nigeria. This rivalry is neither healthy for the nation nor good for the citizens most especially with so many security challenges hanging in the air begging for solutions. What is the relationship between the Nigerian police and the military? What are the reasons for these rivalries? What are the possible solutions to these grudges? To provide answers to these and other questions, the study adopted both descriptive and narrative methods with information derived from both primary and secondary sources. Findings from this study would provide possible solutions to this problem or open new areas for research in this area.