AbstractMental imagery is a transdiagnostic feature that has been increasingly researched in mental disorders in the past years. This study is the first to investigate mental imagery in individuals suffering from Prolonged Grief Disorder (PGD), a new disorder which will be included into the new edition of the International Classification of Diseases and Related Health Problems (ICD-11).Our objective was to find out to what extent patients suffering from PGD differ from healthy, but equally bereaved, controls in terms of mental imagery, and how mental imagery is related to psychopathology. Patients with PGD and matched bereaved healthy controls (n = 54) completed a mental imagery questionnaire specifically designed for the study, and other established measures of psychopathology. Patients suffering from PGD reported mental images more frequently, had less control over them, and described negative images as more vivid than did healthy controls. Also, in reaction to mental images, patients less frequently experienced joy, but more often grief, anger and guilt. Besides these group differences, significant correlations between mental imagery other psychopathological measures could be found. Mental imagery is clearly related to PGD. The underlying mechanisms on whether it is a developing or maintaining factor need to be addressed in future studies. Future research should also investigate in what way mental imagery might be used in therapeutic approaches.