Background <p>Pneumosinus dilatans (PD) is a rare condition characterized by abnormal enlargement of one or more paranasal sinuses without changes to the sinus walls, with the frontal sinuses (pneumosinus dilatans frontalis) being the most commonly affected. To our knowledge, descriptions of pneumosinus dilatans frontalis (PDF) are limited to a cluster of cases, which restricts the development of appropriate diagnostic and management strategies.</p> Case presentation <p>We present a case of a 23-year-old Ethiopian man who has been experiencing intermittent nasal obstruction and headache localized to the frontal region. The discomfort has persisted for over 2&#xa0;years and responds well to over-the-counter analgesics. The patient has a prior diagnosis of chronic frontal sinusitis based on clinical evaluation. During the physical examination, all findings were normal. Routine laboratory tests showed normal results, indicating no underlying systemic issues. Given these findings, the treatment plan included the use of analgesics to manage the pain, along with regular follow-up appointments to monitor the patient’s condition. A CT scan was done to further assess the frontal sinuses and to rule out any other potential complications or underlying causes contributing to the patient's symptoms. The scan revealed that the frontal sinuses were abnormally enlarged, with air-filled spaces, while the sinus walls remained intact and normal in thickness.</p> Conclusions <p>Pneumosinus dilatans is a rare but significant differential diagnosis to consider in patients, particularly young men, when they present with frontal headaches.</p>