Argumentation of uniformity with respect to the Supreme Court has a long tradition and appears in the procedural law context in a variety of ways. It is widely used as a motive for introducing or arguing against changes in the process order, as well as an argument to justify that the Supreme Court must and should act in a certain way. Argumentation of uniformity is further used to legitimize as well as evaluate and criticize the Supreme Court’s role as precedent body. In this doctoral thesis the use and significance of uniformity argumentation regarding the Supreme Court, hereafter the uniformity argument, is examined, analysed and nuanced. A preliminary point of departure for the study is that the uniformity argument may not be as uniform as it appears at first glance. What appears to be the same argument, may in fact hide nuances, different layers or even contradictions, which can be brought to light by studying the uniformity argument more closely in the different contexts in which it is raised.In conclusion, I have highlighted some possible distinctions in the uniformity argument. Among other things, I have pointed to a broader uniformity argument and a narrower one. The broader uniformity argument is described as including both questions of law and questions of fact, in contrast to the narrower uniformity argument which only aims at the position with questions of law. I have highlighted a forward-looking and proactive uniformity argument and a backward-looking and reactive one. I have highlighted that the uniformity argument is used in virtually all contexts where the Supreme Court is discussed or shaped. Furthermore, I have shown how the uniformity argument is used with a variety of uses. I have put my finger on the continuity of the uniformity argument in precedent procedural contexts despite clear changes in the procedural landscape. I have identified that the vagueness of the uniformity argument is important for its resilience, but that this same vagueness can create problems. The thesis has identified, made visible and problematized that the uniformity argument contains different aspects and that different procedural institutes are based on different arguments. This becomes important for the Supreme Court as a precedent instance. The hope is that the results of the thesis will contribute to increasing the rigor in discussions and reforms about the Supreme Court’s operations and focus. In a larger perspective, the study has made visible how a soluble argument such as uniformity acts as a form of meta-norm that gains importance on a variety of levels, for theory formation, legislative policy and procedural rules.