The theoretical grounds for the Millon Clinical Multiaxial Inventory (MCMI) are noted, as are the purposes and features of the inventory. Specified also are the rationale and procedures for constructing the component scales. Both uses and limitations of the instrument are recorded. Steps to be followed in making configural interpretations are recommended. Also reported are results of evaluative research. These point to the general soundness of the MCMI as a clinical tool, as well to areas where ongoing studies may further strengthen its utility in the counseling context.