A retrospective study was conducted to examine the extent to which phobias are associated with a conditioning pathway to fear. The Phobic Origin Questionnaire (Ost and Hugdahl, Behav. Res. Ther. 19, 439-477, 1981) was administered to a sample of 91 phobic outpatients (patients with panic disorder with agoraphobia, social phobics, simple phobics). Results show clearly that conditioning experiences occur more frequently than either vicarious or informational, learning experiences, which confirms the findings previously reported by Rimm, Janda, Lancaster, Nahl and Dittmar (Behav. Res. Ther. 15, 231-238, 1977) and by Ost and Hugdahl (1981; Behav. Res. Ther. 21, 623-631, 1983). Yet, conditioning experiences consist mainly of panic attacks in confirmed environments. The findings also suggest that a considerable number of phobias are based on a combination of different pathways to fear.