This paper discusses three cognitive models for the obsessive-compulsive disorder (OCD). Further, a cognitive formulation of OCD which stresses the importance of the perception of danger and responsibility is described. Several specific cognitive interventions, which address the estimation of catastrophes and the perception of personal responsibility, are presented and illustrated with patient material. Furthermore, problems with cognitive therapy with OCD patients are described and some solutions for these pitfalls are discussed. Finally, the findings of controlled studies into cognitive therapy with OCD are given.