Currently, high-intensity laser therapy (HILT) is increasingly used in various muscle disorders like muscle tension. Our proposed study includes the development of the real-time monitoring system using a myotonometer for HILT. The developed system consists of a piezoelectric sensor and laser distance sensor for muscle stiffness monitoring during the treatments. The results demonstrated that the level of muscle tension was rapidly decreased after 3 minutes of the high-intensity laser treatment when compared to the control group. The combined HILT and realtime muscle tension monitoring system may help to evaluate the therapeutic procedure and efficient treatments for various muscle pains.