The present investigation was intended principally as a concurrent validation study for a new self-report symptom inventory: the SCL-90. A sample of 209 'symptomatic volunteers' served as subjects and were administered both the SCL-90 and the MMPI prior to participation in clinical therapeutic drug trials. The MMPI was scored for the Wiggins content scales and the Tryon cluster scales in addition to the standard clinical scales. Comparisons of the nine primary symptom dimensions of the SCL-90 with the set of MMPI scales reflected very high convergent validity for the SCL-90. Peak correlations were observed with like constructs on eight of the nine scales, with secondary patterns of correlations showing high interpretative consistency.