Objective: Dual-tasking studies show that emotionality and vividness of aversive memory decrease by engaging in a working memory task and simultaneous recall of that memory. Adding positive valence to a dual task might be a promising innovation in the amelioration of lab-induced memory. However, studies aiming to translate these findings into autobiographical memory of a posttraumatic stress disorder (PTSD) population find conflicting results or show methodological flaws. The current study assesses the benefit of adding positive valence to a dual-tasking procedure in PTSD patients. Method: In a cross-over design PTSD patients (N = 33) recalled their traumatic memory and received the following three conditions in randomized order: rating positive pictures + exposure, rating neutral pictures + exposure, and exposure only. Each of the three conditions consisted of four sets of 1 min. In the first cycle, participants were exposed to each condition in a randomized order, which was then repeated in a second cycle. Before and after each condition, emotionality and vividness were rated on a visual analog scale (VAS), resulting in seven measurement timepoints in total. Results: Firstly, repeated measures ANOVAs showed a time effect: memories were less emotional and vivid after our summed (three) interventions. Secondly, repeated measures ANCOVAs indicated no evidence for differences between the conditions. Conclusions: We did not find evidence for a benefit of adding positive valence to a dual-task procedure in PTSD patients.