Given the increasing demand for efficient solutions in physiotherapy rehabilitation, the importance of developing new treatment techniques and computer technologies that can improve the effectiveness of these practices is highlighted. The literature in the area has presented the use of immersive reality applied to rehabilitation, intending to make diagnostic and treatment sessions more interesting, bringing even more specificity to the scenarios of the exercises performed. Based on this assumption, this work’s main objective is to develop a physiotherapy rehabilitation system based on immersive reality that makes it possible to support a more accurate assessment of the exercise execution. A computational system was developed based on HoloLens 2 and the Unity platform as a proof of concept (PoC) composed of two main modules: (i) an immersive environment, which evaluates and provides feedback on the movement performed, and (ii) the virtual assistant, which serves to demonstrate how to perform the movements. The PoC shows that the proposed monitoring system captures and analyzes the angular values of the movement with 98% accuracy. The analysis of the results demonstrates that it is possible to use resources based on iterative immersion to assist professionals who perform diagnostics and treatment protocols for rehabilitation.