Premenstrual Syndrome (PMS) is typically defined as a condition characterized by physical, behavioral, and emotional symptoms that typically appear at the end of the luteal phase of the menstrual cycle, occur 7-10 days before menstruation, and disappear at the onset of menstruation or shortly thereafter. The symptoms of PMS include irritability, a feeling of losing control, anxiety, depression, insomnia, hypersomnia, decreased concentration, and unexplained crying. Symptoms of PMS include irritability, a sense of losing control, anxiety, depression, insomnia, hypersomnia, decreased concentration, unexplained crying, fatigue, weakness, increased appetite, edema, weight gain, dizziness, headaches, joint pain, muscle pain, mastalgia, breast tenderness, aggressiveness, decreased or increased sexual activity, and avoidance of social interactions. Studies have also shown that premenstrual symptoms in young women negatively affect their self-confidence, social relationships, quality of life, and academic performance. For this reason, PMS treatment is important. PMS treatment focuses on alleviating physical and psychiatric symptoms. In PMS treatment, various dietary supplements and complementary-alternative methods can be utilized. Alternative and complementary therapies such as reflexology, pilates, acupressure, music, exercise, and guided imagery have shown promising results in reducing premenstrual symptoms. PMS treatment can be approached from multiple angles. It is important to address the underlying causes of PMS and to consider the individual's overall well-being.It is known that mind-body-based approaches in complementary and alternative medicine have a healing effect on individuals from a psychological perspective. Guided imagery is a form of mind-body communication and is defined as a stream of thoughts or the way in which our minds encode, store, and express information based on what we smell, taste, see, hear, and touch. Guided imagery is based on the understanding that the body and mind are interconnected and that the mind can influence the body. Guided imagery has been found to be effective in various situations, such as reducing stress, improving mood, strengthening the immune system, reducing fatigue, improving sleep quality, and minimizing nausea and vomiting. There are very few studies in the literature on the use of guided imagery to reduce symptoms in university students during the premenstrual period. The aim of this study is to investigate the effect of guided imagery on premenstrual syndrome in university students.