Mental images are cognitions, which take the form of sensory experiences in the absence of a direct percept. Images can be opposed to verbal thoughts, i.e. cognitions in the form of words. From the perspective of clinical cognition, verbal thoughts and mental images are different phenomena, with mental images having tighter connections to emotion than verbal thoughts. Recently, cognitive psychology research has focused on spontaneous mental imagery, i.e. involuntary intrusions of often vivid mental images that appear in one’s mind. Spontaneous mental imagery is now viewed as an important part of psychopathological processes across psychological disorders, a potential emotional amplifier and a therapeutic target in its own right. Pain is a personal experience, so exploring and understanding the patient’s thoughts about pain might contribute to therapeutic success and favour personalized care. In the field, thoughts about pain have been mostly studied as verbal thoughts. Yet, a growing literature is investigating thoughts about pain in the form of imagery. Studying chronic pain patients’ mental imagery provides unique insight into their personal experience, integrating information about somatosensory perceptions, emotional experience and meanings of pain. The study of imagery in pain also gives insight into possible reinforcing mechanisms of pain, and a basis for a powerful, individualized therapeutic approach through different mental imagery therapy techniques. This chapter describes current knowledge about mental imagery as intrusive cognitions in the context of pain, considers the neuroscientific investigations that have been undertaken, and discusses the therapeutic potential it yields.