Two faculties from the University of Split are members of CMS: the faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, and the faculty of Science. Split groups have been members of CMS since 1994. At the moment the Split groups consist of seven professors, three postdocs, four PhD students and two technicians. They are involved from the very beginning in the design, development and construction of the Electromagnetic Calorimeter, particularly in the development and testing of the ECAL photodetectors as well as electron reconstruction, which contributed to the discovery of the Higgs boson through its decay into four leptons. At the moment the groups are involved in the upgrade activities of the High-Granularity Calorimeter and continue to work on the electron reconstruction and Higgs physics.