After a 4-week waiting period 21 obsessive-compulsives were randomly allocated to two treatment conditions (1) Rational Emotive Therapy (RET) and (2) exposure in vivo. RET consisted of analysing irrational thoughts; exposure in vivo was self-controlled. After six sessions and another 4-week waiting period all patients received six sessions of exposure in vivo. Both treatments resulted in significant improvement on anxiety/discomfort, Maudsley Obsessional Compulsive Inventory, and Dutch Obsessional Compulsive Questionnaire and in a reduction of scores on the Irrational Beliefs Test. Results were maintained to a follow-up 6 months later. No significant differences were found between the two conditions. © 1991.