The incidence and extent of irrational beliefs in the obese were investigated as well as subsequent changes in such beliefs as a result of participation in a self-monitored weight control program. Subjects were 53 females who were a minimum of 10 pounds and an average of 32 pounds overweight. The obese sample was administered the Irrational Beliefs Tests and also participated in individual counseling sessions over a nine-week period. The control group consisted of 32 female counselor trainees. Results indicate that: (1) a decline in overall irrationality corresponded with a successful treatment program; (2) obese and non-obese participants did not differ in psychological make-up; (3) obese persons entering the program believed it is easier to avoid than face problems; and (4) after completion of the program, the obese sample declined in anxious overconcern, Scale Six of the Irrational Beliefs Test. (Author/HLM)