Compared six MMPI short forms for their ability to identify code-types and indices of psychopathology obtained from the full length MMPI for samples of renal dialysis patients (N = 53) and paranoid schizophrenics (N = 58). Results suggest that the accuracy of the short forms fluctuates for different patient populations and diagnostic criteria. The longer abbreviated forms are generally more accurate, especially the MMPI-168 and the FAM.