Abstract Objective: The present study explored the resources reallocation explanation for memory biases in posttraumatic stress disorder (PTSD), whereby a preferential allocation of cognitive resources to the processing of threatening stimuli could result in both improvements in their memorization and deficits for other types of information. Method: To this end, 25 participants presenting significant symptoms of PTSD (i.e., total PCL-5 score ≥33) and 32 participants presenting low levels of symptoms (i.e., total PCL-5 score <20) took part in a Remember/Know recognition procedure associated with a dual-task encoding of positive, neutral, negative, and trauma-related words. In order to manipulate the availability of cognitive resources, the encoding of each word was associated with a simultaneous encoding of series of letters and numbers. Results: Results replicated the increased production of Remember recognitions for trauma-related words in participants with significant PTSD symptoms. However, the dual-task load only impaired remember recognitions for non-trauma-related words. Conclusions: Contrary to expectations, these findings suggest that the encoding of trauma-related information in PTSD is relatively independent from the availability of cognitive resources. Thus, rather than reflecting an increased allocation of cognitive resources to the processing of threatening information, memory biases in PTSD appeared to be supported by an enhanced efficiency of their processing.