This study was conducted to determine the impact of mindfulness-based therapy on psychiatric symptoms, psychological well-being, and pain beliefs in patients with lumbar disk hernia. Design and Methods: The study was a nonrandomized pretest-posttest controlled quasi-experimental research and carried out in a total of 64 patients. A personal information form, the Depression Anxiety Stress Scale, the Psychological Well-Being Scale, and the Pain Beliefs Scale were used for data collection. Findings: We observed a statistically significant difference between the intervention and control groups in terms of the posttest mean scores of the psychiatric symptoms, psychological well-being, and pain beliefs. Practice Implications: The results revealed that mindfulness-based therapy has a positive impact on pain beliefs and psychological well-being. K E Y W O R D S lumbar disk hernia, mindfulness-based therapy, psychosocial status 1 | INTRODUCTION Lumbar disk herniation (LDH) is a disease that restricts the activities of individuals in daily life and is common in the community. 1 The most common symptom among patients diagnosed with LDH is pain, which should be considered as a multidimensional feeling. 2 Encountering a sudden pain causes a serious effect on the psychological states of individuals. 1 These effects include one's fear of being dependent on others, the anxiety of death, fear that some parts of the body will be maimed, and concerns about being unable to meet economic needs. 3 The patient, whose psychological state is affected, experiences emotional reactions, and the extent of which may vary depending on the physiological process, such as anger, irritation, denial of the disease or condition, helplessness, and frustration due to the fear of dependence on others. 3,4 These reactions often cause psychiatric disorders in individuals. The symptoms of anxiety and depression increase even more if the patient has severe lumbar pain, complicating the compliance of the patient to the treatment. 1 To facilitate the adaptation of the individuals to the treatment process, the stressful situations they experience should be identified and solved through appropriate nursing interventions. Mindfulness-based therapy (MBT) can be used to cope with the pain, anxiety, stress, and depression experienced by individuals in different patient groups. 5-7 The concept of consciousness is defined as living the instant experiences and admitting and acknowledging the moment without being influenced by the possible experiences and emotions gone through in the past or planned for future. 8 Consciousness is the momentary experience in which the person concentrates his or her attention on that moment, that is, the present, and admits it without any judgment. MBT also includes methods that enable one to focus on that particular moment. With the administration of these methods, one learns the strategies of coping with problems, accepting internal and external experiences, and avoiding. 9 MBT-applied research has been conducted on cancer patients, 6...