Background and Aim: Sleep quality has a fundamental and important role in determining the physical and psychological health of humans. Sleep disorders are widespread and have very damaging effects on the individual and social aspects of human life. This research was aimed to evaluate the effectiveness of hypnotherapy on sleep quality improvement.

Materials and methods: The method research was a Quasi-experimental, and pretest-posttest design with the control group. The population was all students of Applied Science Center of Khorasan Razavi in 2014. The sample consisted of 30 volunteers who were randomly assigned to two experimental and control groups, each group 15 subjects. Pittsburgh Sleep Quality Index was used to assess the sleep quality, and Wilkinson (1981) protocol was used for hypnotherapy sessions. Research data were analyzed by using the analysis of covariance.

Results: The results show the effectiveness of hypnotherapy to improve the overall quality of sleep, subjective sleep quality, sleep latency, sleep disturbances, and daytime dysfunction.

Conclusion: hypnotherapy improves sleep quality through mechanisms such as reduced physiological arousal, stimulation of relaxation, release stress and cognitive changes. It is suggested the use of this treatment in the sleep problems and more research in this area due to the lack of studies.