The article presents a clinical example of the course of posttraumatic acute purulent sinusitis with reactive soft tissue phenomena due to the previous injury of the orbit by a foreign body, the introduction of the latter into orbit and the maxillary sinus result in a fracture of the lower wall of the orbit. A feature of the injury is the penetration of a foreign body through the conjunctiva of the lower eyelid and lower conjunctival fornix, without damaging the skin. This case is professionally interesting for both young doctors and experienced specialists in otolaryngology, ophthalmology, maxillofacial surgery and neurosurgery. Experts, analyzing this clinical example, will be able to correctly diagnose, effectively eliminate the inflammatory process in the maxillary sinus.