This randomized controlled trial investigated the effects of online guided imagery interventions on traumatic memory processing in adults at risk for Complex PTSD (CPTSD). 88 South Korean adults at risk for CPTSD were randomly assigned to either imagery rescripting (IR), imagery rescripting-other (IRO), or control group. In addition to IR components, IRO additionally included other-nurturing imagery. Both the treatment groups had positive changes in affect, trauma-related emotions, and cognitive appraisals that persisted after 1 week. The treatment groups did not differ in their effects on affect regulation, but IR had greater changes in cognitive appraisals than IRO.