Abstract: The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is one of the most widely utilized psychodiagnostic instruments used with Latinos in the United States. Literature regarding the utility of the MMPI-2 to differentiate between diagnostic groups with Mexican-Americans is scant. There appears to be even less research concerning the clinical correlates of both individual clinical scales and MMPI-2 code types. The primary purpose of this study was to examine the ability of the MMPI-2 to aid in differential diagnosis within a psychiatric outpatient Mexican-American sample. In order to accomplish this task, the researcher evaluated which of the Clinical and Content scales on the MMPI-2 were related to two diagnostic groups, depression and schizophrenia, and sought to measure the scales' efficacy in prediction of diagnostic group membership through the use of multivariate and univariate analysis of variance. The analysis included two supplementary analyses. The first supplementary analysis was conducted in order to determine clinical correlates of MMPI-2 two-point code types within the sample. The second supplementary analysis examined the diagnostic efficacy of the MMPI-2 with Mexican-American outpatients by observing the sensitivity and specificity of individual scales designed to assess depression and psychoticism. Participants for this investigation included 139 Mexican-American psychiatric outpatients. An additional 19 participants were excluded due to profile invalidity (Total original N = 158). Within the group of 139 participants, 37 had a primary DSM IV axis I diagnosis of schizophrenic spectrum disorder, while 57 had a primary axis I diagnosis of a depressive disorder. Comparisons between depressive and schizophrenic outpatients, on the basic Validity, Clinical, and Content scales, were statistically indiscriminant. This is inconsistent with studies observing other clinical samples. Results of code type analysis revealed similar correlates to those found in the literature for the 68/86 code type, offering support for interpretive use of this code with Mexican-American outpatient samples. The second supplementary analysis examined the sensitivity and specificity of four MMPI-2 scales theorized to predict depression or schizophrenia. Clinical scales Depression and Schizophrenia, and the content scale DEP, were found to hold poor diagnostic efficiency. The exception to this group was the content scale BIZ, which showed moderate diagnostic capabilities.