The objectives of this investigation were to develop, implement, and determine the effects of rational behavior therapy for residents in a retirement community. The question addressed was, "Will rational behavior therapy, relative to a discussion group and control group, exhibit significant changes in level of rational thinking and depression?" Drawing upon a cognitive theory of depression relevant to the aged population and upon rational behavior therapy literature, it was hypothesized that short-term rational behavior therapy intervention would be significantly related to a modification of belief systems and a decrease in depression. The participants were residents of two retirement communities. There were 25 subjects who completed the study through posttest assessment. These subjects were randomly assigned to three groups and assessed at pretest, posttest, and follow-up. The experimental group did not experience the hypothesized significant increase in level of rational thinking and decrease in level of depression. Possible explanations are given for lack of expected effects. Overall, the discussion group had more significant increases in rational thinking than the experimental and control groups.