Between 40 and 60% of patients with obsessive-compulsive disorder (OCD) are resistant to conventional pharmacological and psychotherapeutic care. The latter, in the forefront of which are exposure and response prevention techniques, are likely to benefit from the rise of virtual reality (VR). However, very few studies have been conducted on the use of VR in OCD and these suffer from several limitations including a lack of ecological validity. This proof of concept study aims to evaluate a personalised exposure protocol using immersive video in a patient suffering from severe and resistant OCD. This protocol consisted of 15 weekly sessions of exposure via a VR headset to 360° immersive videos filmed from the subject’s viewpoint in their own environment. Besides the high acceptability of the immersive device, our patient exhibited a therapeutic response with a reduction in emotional responses measured by skin conductance recording, a reduction in obsessive-compulsive symptoms and an improvement in quality of life. This study thus provided promising results in a patient initially refractory to conventional treatments. Replication of these results on a sufficiently large group of patients would place personalised immersive 360o video exposure as a technique of choice in the therapeutic arsenal for OCD due to its cost-effectiveness and high acceptability.