This article describes and further validates a standardized symptom-provocation procedure that combines symptom-specific audio instructions and pictures to reliably provoke different kinds of symptom-specific anxiety in obsessive-compulsive disorder, corresponding to its four major symptom dimensions: contamination/washing, obsessions/checking, hoarding and symmetry/order. The Maudsley Obsessive-Compulsive Stimuli Set has excellent convergent and discriminant validity, and it will be a useful resource for OCD researchers.