Increasing evidence supports the idea that client expectancies have a large impact on counseling relationships, processes, and outcomes. Research and theories regarding expectancies are examined in this paper. Albert Bandura's theory of self-efficacy is discussed first to provide a background for understanding the significance of efficacy expectations. According to Bandura, self-efficacy expectations affect all situations. It is argued that since self-efficacy beliefs govern people's behaviors, changes in behavior, motivation, and affect, then Bandura's theory can be applied to all aspects of life. How the theory can be applied to psychotherapy is described, and its impact on counseling is discussed. Next, the research of Howard Tinsley, who developed the Expectations About Counseling Scale, is also considered. Some of the various expectancies in counseling are examined and special attention is given to the controversial aspects of the literature, especially Tinsley's emphasis on the manipulation of client expectations to achieve effective counseling. A description of problems with research methodology used to measure expectancies is also covered. (RJM)