In this article a cognitive therapy of obsessions is described with two patients with an obsessive-compulsive disorder. The treatment consisted of (a) an explanation of the cognitive model with an emphasis on the difference between intrusions and negative automatic thoughts, (b) repeated explanation about intrusions – intrusions are normal and increase by thought-suppressing – on the basis of research and the ‘white bear’ experiment, (c) changing the negative automatic thoughts by discussion and (d) behavioural experiments to verify the correctness of the interpretation. Both patients strongly improved. Although they still had intrusions, occasionaly, it didn't make them anxious any more, nor did they perform any (cognitive) rituals. Both patients show that cognitive therapy may be a succesfull treatment for obsessions.