Abstract: Researchers and psychotherapists have long been interested in specifying as completely as possible the ongoing process variables occurring between therapist and client which lead consistently to effective therapeutic relationships and positive psychotherapy outcomes. Although a number of these variables have been intensely studied, few definitive findings exist. The purpose of the present study was to further the specification of the components of the successful relationship through investigation of a heretofore little researched area that has been the subject of a great deal of theorizing. Grinder and Bandler (1976) have argued that individuals, while taking in information from all senses, show a preference for representing their experience internally in a particular, favored, modality. This modality, by virtue of its greater usage, has available in it greater and finer distinctions in the world of experience. It constitutes, therefore, a more cognitively complex map of the world than the corresponding map in another modality with fewer distinctions. When describing their experience to themselves or others, individuals choose predicates which emphasize content from this more highly differentially favored system. Grinder and Bandler suggest that communicating to a client in predicates which imply the client's most favored modality serves, through greater clarity and ease of understanding, as a basis for the client's experience of rapport with the therapist. By the same token, communication across sensory channels may result in a loss of precision and be a component of misunderstanding or confusion between therapist and client. To test this hypothesis of a higher level of experienced rapport for clients who have been systematically matched, versus mismatched, in terms of the sensory modality implied by their predicate choice, 24 subjects were randomly assigned to 1 of 2 possible treatment session sequences. In one group, the clients were given 2 1-2 hour analogue therapy sessions where the therapist systematically matched their predicates in the first session and mismatched them during the second. The other group received the opposite order; that is, the therapist mismatched during the first session and matched during the second. During the match session, the counselor made a concerted effort to match the predicates spoken by the clients in terms of the sensory modality implied by their predicate choice. In the mismatch condition, the counselor mismatched the predicates spoken in terms of the sensory modality implied. To ensure that the match or mismatch procedure has been accurately administered, trained judges listened to audiotapes of the sessions and discarded those failing to meet the criterion. From the final pool, 8 subjects were removed leaving a total n of 16. At the end of each session, clients filled out the Session Evaluation Questionnaire (Stiles, 1980) and the Barrett-Lennard Relationship Inventory (1962) Empathetic Understanding Scale and Level of Regard Scale. Comparison of the means of the total match and mismatch samples through use of the correlated samples t-test revealed significant differences (t=2.28, df=14, p(.05) between groups on the Empathetic Understanding Scale of the Barrett-Lennard, but not on the remaining measures. These findings were interpreted to support the Grinder-Bandler hypothesis that systematic matching of a client's predicates in terms of sensory modality implied, facilitated the client's perception of the empathetic component of rapport in the therapist above the case where the therapist mismatches. The procedure, however, had no discernable impact on the client's perception of level of regard or the Stiles (1980) measures of Depth/Value, Smoothness/Ease, or perception of therapist level of regard is determined by other factors than those involved in the matching procedure. Too, it was suggested that the Stiles measures were more dependent on session content than interactional factors. Interesting anecdotes drawn from the counselors' experience during the study were discussed to highlight some of the subtleties of the matching procedures not readily apparent. A number of directions for further study in the area were offered.