In this review the results are discussed on the prediction of response to pharmacotherapy in panic disorder (PD) and social phobia (SP). From the literature it appears that in PD variables indicative of illness severity are predictors of non-response. In our own studies we found that non-responders to pharmacotherapy in PD are characterised by a higher score on the Blood-Injury subscale of the Fear Questionnaire, a higher plasma MHPG and a higher heart rate. In SP non-responders to pharmacotherapy were also characterised by a higher heart rate. They also appeared to have a higher blood pressure. Furthermore non-responders to pharmacotherapy in SP had higher scores on several psychometric scales, indicative of illness severity.