Evidence is growing that two modalities of computer-based exposure therapies--virtual reality and computer-aided psychotherapy--are effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for fear of flying: virtual reality exposure therapy (VRET), computer-aided exposure with a therapist's (CAE-T) assistance throughout exposure sessions, and self-administered computer-aided exposure (CAE-SA). A total of 60 participants with flying phobia were randomly assigned to VRET, CAE-T, or CAE-SA. Results indicate that the three interventions were effective in reducing fear of flying at posttreatment and at 1-year follow-up; furthermore, there were no significant differences between them in any of the outcome measure. Large within-group effect sizes were found for all three treatment conditions at both posttreatment and at follow-up. The results suggest that therapist involvement might be minimized during computer-based treatments and that CAE can be as effective as VRET in reducing fear of flying. (Contains 3 tables.)