<p>Mathematics curriculum standards have become a major component of most educational systems. They define what a student should learn at each grade. The political question that accompanies the standards and all of its related components is, who makes what decisions. In this study, a senior-level mathematics administrator from each of 19 countries was asked to indicate who made what decision, if any, for each of 14 components related to the development of the national standards. The focus of the study was on teachers both collectively and individually. Three other stakeholders (national administration, regional administration, and schools) were included as well. The data (related to the OECD 2030 project) indicated a very large variation across countries and across the 14 areas on curriculum construction such as goals for teaching in terms of teacher involvement. Not only did the data indicate whether teachers were involved in the process but more importantly indicated the degree of authority they had in the process which varied appreciably across countries. Given related data from TIMSS 1995, this study also showed large variation from what was true of the teachers’ role in curriculum decision making some 25 years ago. Unfortunately, the previous data does not include an indication of the degree of authority the teacher had in the process, only whether or not the teacher was involved. The comparison across the two studies indicated a major increase in the involvement of teachers in the curriculum decision making process.</p>