Taking into consideration the importance of cognitive factors in behavior therapy, this article argues that the role played by awareness has until now been understudied in this field of therapy. A review of the literature concerning verbal conditioning, classical conditioning, knowledge of results as reinforcement, self-monitoring, effeaiveness of covert and oven practice in the treatment of phobics, perception of self efficacy, and treatment by habit reversal indicates that awareness is an implicit variable present in each case. A reinterpretation of these areas of research is presented. In addition, when this variable is evaluated systematically, the results indicate that the therapeutic impact of awareness has been underestimated. Some potential clinical applications of this position are discussed as are some new avenues of research.The role of cognitive factors in behavior therapy is the subject of considerable discussion (Ladouceur, Bouchard, & Granger, 1977). However, it would be naive and inexact to define all the various aspects of cognitive factors under the same method of treatment. While Ellis (1977) deals mainly with the irrational beliefs haboured by the client, Meichenbaum (1977) aims first and foremost at changing the negative self-verbalizations of the individual, and Beck (1976) seeks to correct the perceptions of depressed patients. On the other hand, Bandura (1977a) elaborates a model of learning which emphasizes the expectations of the subject. According to this construct, the reinforcement does not act as a stimulus-consequence to establish an automatic link between two stimuli but rather as an agent which focuses the subject's attention so that he obtains the maximum information from a given situation. In spite of these differences in the specific processes postulated, several adherents to the cognitive approach agree that the cognitive processes of the individual significantly influence observed behavior and that any therapeutic procedure should directly modify these processes, as a function of the basic postulates of each therapeutic model.Among the cognitive variables commonly postulated (within a mediational model of learning), one finds the following: attention, retention, symbolic coding, short-term and long-term memory, competence, expectancies, and mental imagery (Bandura, 1977a;Mahoney, 1974). It is surprising to find that a phenomenon like awareness has only rarely been approached as a cognitive variable 'directly influencin~ behavior.