The relative efficacy of cognitive restructuring and interoceptive exposure procedures for the treatment of panic disorder, as well as the differential effects of the order of these interventions, was studied. Eighteen clients with panic disorder were seen for four sessions of exposure therapy and four sessions of cognitive therapy in a crossover design study. Half of the participants received exposure therapy followed by cognitive therapy and for half the order was reversed. There was a 1-month follow-up period between the two interventions and after the second intervention. Questionnaire measures and independent clinician ratings were used to assess outcome. Participants expected greater benefit from cognitive therapy, but tended to improve to a similar degree with either intervention. The order in which treatments were presented did not influence outcome. Participants tended to improve with the first intervention and maintain improvement across the follow-up periods and subsequent intervention. Several methodological limitations qualify the conclusions that can be drawn from this study. These limitations, as well as some conceptual and methodological challenges of conducting this type of research, are discussed.