Malingering is not a diagnosis, but is a V-code classification that should be considered in the differential diagnosis of other disorders. This chapter discusses the prevalence of malingering and construct drift, and the assessment of malingering. Rogers (2008) described the major advancements in malingering evaluations, which progressed from idiosyncratic case methods and scale differences on psychological measures to systematic detection strategies. The chapter provides a sampling of detection strategies for feigned mental disorders and feigned cognitive impairment. In closing, determinations of malingering are complex multifaceted assessments that involve (1) the selection of a malingering domain, (2) administration of well-validated measures to evaluate detection strategies systematically and (3) careful investigation of different motivations. Most practitioners use the Structured Interview of Reported Symptoms (SIRS) and one multiscale inventory (Minnesota Multiphasic Personality Inventory (MMPI-2) or Personality Assessment Inventory (PAI)) in their determinations of feigning.