A clinical experiment comparing methods of fear reduction in claustrophobia was used as the basis for analysing the relationships between a number of cognitive variables and the reduction of claustrophobia. Both the number and believability of negative cognitions present were associated with fear reduction and return of fear; this was also found when considering the number of body sensations experienced. High fear and panic were always accompanied by these phenomena whilst zero fear was never reported in the presence of believable cognitions and body sensations. An absence of believable cognitions post-test was accompanied by an absence of claustrophobia in 10/13 subjects. Specifically, removal of belief in any of the cognitions "I will be trapped", "I will suffocate" and/or "I will lose control" was associated with removal of belief in all the other cognitions and a dramatic reduction in claustrophobia. Belief in one of these central cognitions was associated with the maintenance of fear. We conclude that it is possible to conceptualize claustrophobia as comprising a number of cognitions centred on key thoughts of trappedness, suffocation and loss of control.