Social interaction may be construed as a process of mutual and reciprocal interpersonal influence. Counseling and psychotherapy are not different from other types of social interaction in this regard. Counselors influence clients and clients influence counselors. This study investigated the dynamics and patterning of social influence and relational control between a counselor and client across a 12-session counseling case. Counselor and client verbal utterances were coded in terms of their implied relational positions (one-up, one-down, one-across) using Heatherington's (1985) modification of Erickson and Rogers' (1973) relational coding system. A measure of the degree of dependence/contingency between counselor and client responses served as an index of social influence and relational control. Variations in the degree of contingency between responses were plotted across the 12 sessions and evidenced three distinct phases of the counseling process. Results indicated the vast majority of responses were one-across, responses which minimize or neutralize the relational control aspect of communication. The counselor was shown to be more domineering than the client, though not necessarily dominant. Although this study was based on a single case, it did confirm previous research. Twenty-eight references are appended. (Author/ABL)