Pneumosinus dilatans is a rare disease that most commonly occurs in young men. It is characterized by an hyperpneumatization of sinus cavities. Its etiopathogenis remains unclear. The bony and mucosal structures are normal and there is no sinus disorders associated with. Most of patients with pneumosinus dilatans present with a cosmetic complaint. METHODS We report a new surgical technique performed in a young male with bilateral frontal pneumosinus dilatans. A Bi-coronal incision makes it possible to largely expose the anterior wall of the frontal sinus. This wall is then weakened by drilling which should not be transfixiant. A soft impaction of the weakened wall of the sinus, by avoiding any effraction of the sinusal mucous membrane allows a reduction in volume of the frontal sinus with disappearance of the sus-orbital tumefaction. Cosmetic and functional outcomes, 18 months after surgery are good and stable. CONCLUSIONS This technique of impaction, without sinusal bone window nor osteosynthesis or bone grafting, preserves the integrity of the sinusal mucous membrane while guaranteeing a good cosmetic result.