To examine the relationship between preference for group psychotherapy and adherence to group cognitive-behavioral therapy (CBT) for clients with panic disorder with agoraphobia (PDA), 109 participants experiencing PDA completed a questionnaire measuring preference for group treatment (PGTQ) before beginning CBT groups. A t test was used to compare preference scores for group treatment to investigate whether participants who completed treatment differed from those who abandoned treatment. Participants who completed group therapy expressed higher preference for group treatment than participants who dropped out of treatment (t[107] = 1.99; p < 0.05). The PGTQ-4 presented adequate psychometric properties. Reliability analyses of the items retained after factorization demonstrated an acceptable level of internal consistency (Cronbach's alpha of 0.76). Preference for individual or group therapy appears to impact treatment retention for patients with PDA. Matching patients' preferences to the type of treatment modality used appears to be pertinent, especially for the treatment of anxiety disorders. In terms of practical implications, the rationale and benefits of group therapy should be explained to participants reluctant to engage in group therapy. Individual intervention or a combination of group and individual treatment could be considered for clients who are likely to drop out of group therapy.