Although the 1995 constitution of the Federal Democratic Republic of Ethiopia (FDRE) and the 2001 revised constitution of the Southern Nations, Nationalities, and Peoples' Region (SNNPR) impose obligations on federal and regional governments, the constitutional principles of self-determination do not align with the operational realities in Southern Ethiopia. A gap exists between rhetoric and reality. This article examines the concordance between constitutional principles and operational realities in establishing new regional states in Southern Ethiopia. A mixed-methods research approach was employed to collect and triangulate data alongside relevant literature. The research findings indicate that the claim of Nations, Nationalities, and Peoples (NNPs) for self-determination has encountered significant obstacles. The constitutional rights outlined in Articles 39 and 47 have not been effectively implemented in Southern, Central, and Southwestern Ethiopia, designated as multiethnic clustered regional states. In contrast, Sidama, organized as a mono-ethnic regional state, enjoys certain constitutional rights that other new regional states do not. Consequently, the government and the ruling party should address the claims for self-rule concerning the right to establish a separate regional state and learn from the failures of SNNPR.