This chapter reviews the most prominent instruments for assessing malingered mental illness and its symptoms. The Structured Interview of Reported Symptoms (SIRS) has been regarded as the gold standard instrument in this area, but a recent revision, the SIRS-2, has come under considerable criticism that extends to its predecessor as well. Although the SIRS-2 may produce fewer false positives than the original SIRS, especially in intellectually disabled examinees and perhaps in examinees with dissociative identity disorder, it is less sensitive than the original SIRS and may misclassify a substantial number of of feigners as genuine. The strengths and weakness of instruments in this domain, such as the M-FAST and SIMMS, are discussed along with the costs of their use (time and money), diagnostic statistics, and recommended cutoff scores.