Proximal humerus fractures most commonly affect adult population. They make 5% of total number of fractures with rising rates at an older age. In treating the fracture, the goal is to achieve a clinical condition of painless shoulder, restore the function of the shoulder and to provide the patient with care for themselves. Treatment options are conservative and surgical: osteosynthesis and arthroplasty. The aim of the study was to investigate functional results after reverse total shoulder arthroplasty in the multifragmental proximal humerus fracture. In the period from January 2016 until December 2017 at the KBC Zagreb, Traumatology Department, in 12 patients the procedure of the reverse total shoulder arthroplasty was performed, of which 8 were women and 4 men. The average age of patients was 74.2 years (range 63-88). In patients, we investigated the level of pain, satisfaction with the results of the operation, a QuickDASH score, a roughly estimated range of motion, and radiological findings. Of the 12 operated patients, to evaluate the pain and function of the shoulder, 8 subjects were available. Out of the total of 8 respondents, 4 indicated that pain was not present at all, 4 that the pain occurs occasionally, and 0 that pain is constantly present. The mean rate of pain ranging from 0 to 10 was 2 (SD = 2, range 0 - 5). The mean satisfaction value of the operation results on a scale from 0% to 100% is 77.5% (SD = 10.6, range 50-95). Of the 8 subjects in anteflexion of the hand over the head can raise 5 subjects, the arm on the top can set 5 out of 8, and the wrist of the operated hand behind the back can be set by 4 examinees. The QuickDASH score was measured in 7 out of 8 available subjects with a mean measured value of 26.3 (SD = 6.4, range 13.6 - 35.0). The conducted research has yielded good results with regard to pain and limitations in daily activities.