Of 49 compulsive ritualizers one-third perceived their obsessive thoughts as a rational and felt that their rituals warded off some unwanted or feared event (the content of their obsessions). The more bizarre the obsessive belief the more strongly it was defended and 12% of cases made no attempt to resist the urge to ritualize. Neither fixity of belief nor resistance to compulsive urges were related to duration of illness. Patients with bizarre and fixed obsessive beliefs responded as well to treatment (all but three received exposure), as did patients whose obsessions were less bizarre and recognized as senseless. There was no difference in outcome between patients who initially found it hard to control their obsessions or never resisted the urge to ritualize and those who initially could control obsessions or resist rituals. One year after starting treatment, patients whose obsessions and compulsions had improved with treatment recognized their irrationality more readily and controlled their compulsive urges more easily. Beliefs appeared to normalize as a function of habituation.