The purpose of this study was to address the question: Is the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) comparable to the original MMPI in its applicability to the assessment of posttraumatic stress disorder (PTSD) among Vietnam combat veterans? The question was addressed by administering both the original MMPI and MMPI-2 to 29 subjects classified as meeting Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; DSM-III-R) criteria for PTSD and comparing MMPI and MMPI-2 scores in terms of: degree of association, code-type congruence, diagnostic hit rates (when compared to two other clinical samples, and one normal sample), and congruence of the Keane PTSD Scale (PK). Results reveal highly significant correlations between MMPI and MMPI-2 basic scales for the PTSD sample as well as congruence in 2-point codes comparable to previous studies. The MMPI-2 was found to identify effectively PTSD subjects from the other groups. Results also showed a high degree of association between the MMPI and MMPI-2 in regard to PK scores, although minor differences were found in PK raw scores between the two tests. Overall, the findings suggest a high degree of comparability between the MMPI and MMPI-2 in the assessment of PTSD.