Hyperventilation is assumed to produce a set of somatic and psychological symptoms, the so-called Hyperventilation Syndrome (HVS). Recognition of symptoms during the hyperventilation provocation test (HVPT) is the most widely used criterion for diagnosing HVS, but additional physiological and symptom criteria have been proposed. The concordance of various diagnostic criteria for HVS is investigated in the present study. Forty-eight psychiatric patients with panic disorder and 90 somatic patients with symptoms suspective of HVS performed a HVPT. There was a strong interrelationship between the various symptom criteria as well as the physiological criteria. However, almost no association between symptom and physiological HVS criteria were found. Symptom recognition was significantly related to trait anxiety, agoraphobia and depression. These data do not only question the validity of the HVPT, but also of the concept of HVS. The results are more consistent with a cognitive approach to anxiety in which the HVPT is seen as an aspecific stressor during which more anxious patients anticipate an anxiety attack.