Malingering is likely to occur when one has a lot to gain or lose from the existence of a physical injury or mental disease or defect. There are many procedures in place to help professionals determine whether or not one is malingering that follow either the global-signs-of-lying model or the accuracy of knowledge model, which rely on physiological and cognitive criterion, respectively. The present study aims to determine whether or not a claim of ambidexterity might be a potential indicator of malingering. 310 reports from an experienced neuropsychologist were analyzed and coded for statistical analyses. Comparisons between clients who claimed single-handedness and clients who claimed ambidexterity, primarily in Rule 11 competency to stand trial evaluations, support the hypothesis that clients who claim ambidexterity are more likely to be malingering. This information opens the door for more research on the use of this criteria in making a clinical judgment on malingering.