Cognitive behavior therapy (CBT) is an effective treatment for late life anxiety and depression. The successful use of CBT is assumed to rely on cognitive skills known as executive functions (EF; e.g., hypothesis generation, allocation of attention, self-monitoring) governed by the prefrontal cortex. Because older adults sometimes have executive deficits as a consequence of normal aging, EF may be a mediator of CBT outcome in older samples. The current pilot study tested the hypothesis that older adults with executive deficits (as measured by neuropsychological tests) would show decreased therapeutic benefit from CBT for generalized anxiety disorder, as compared to a group with intact EF. Results indicated differential response to CBT within the dysfunction group depending on the stability (and possibly, the etiology) of executive deficits from pre- to posttreatment. Those whose EF scores remained low from pre- to posttreatment did not respond to CBT, while those whose scores improved responded quite well, similar to an Intact EF group. Results indicate that some, but not all, older adults with executive dysfunction show decreased benefit from CBT, and are consistent with the assumption that executive skills are important for the successful use of CBT. However, some participants may show improvement on both mood and cognitive skills during treatment, which is discussed further.