To test predictions derived from the emotional processing theory of fear reduction, claustrophobics (N = 58) were randomized to one of four exposure conditions: (a) exposure with guided threat reappraisal, (b) exposure with a cognitive load distracter task, (c) exposure with both guided threat reappraisal and cognitive load distracter task and (d) exposure without guided threat reappraisal or cognitive load distracter task. We hypothesized that self-guided in vivo exposure would lead to less fear reduction if performed simultaneously with a cognitive load distracter task that severely taxes information processing resources. In contrast, we hypothesized that focusing on core threats during exposure would enhance fear reduction. The main findings were largely consistent with predictions. The cognitive load task (regardless of focus of available attention) had a detrimental effect on fear reduction, while guided threat reappraisal (regardless of cognitive load) had a facilitative effect. The greatest level of fear reduction and the lowest level of return of fear were observed in the exposure condition involving guided threat reappraisal without cognitive load. Clinical implications and directions for future research are discussed.