Self-monitoring has become a popular assessment tool in treatment outcome r
esearch and descriptive psychopathology for panic and anxiety disorders. Co
mmonly used formats of self-monitoring for each anxiety disorder are descri
bed. Self-monitoring is compared with self-report estimation. On the one ha
nd, self-monitoring may be influenced by reactivity, as well as by attentio
nal and judgmental biases that underlie fear and anxiety. On the other hand
, self-monitoring may minimize certain influences that tarnish estimation,
such as response demand biases, memory deficits, inflation of aversive expe
riences, and availability heuristics. Issues for statistical analysis of se
lf-monitored data for panic and the anxiety disorders are outlined. Finally
, directions for future research and clinical use of self-monitoring are di
scussed.