Introduction Although computed tomography scanning is the most common method for the diagnosis of sinusitis today, X-ray imaging is still used in outpatient clinics. Because X-ray imaging is beneficial for patients with severe sinusitis but not for those with mild sinusitis, an alternative method to visualize sinusitis without X-ray imaging is desirable. Objective To study the possibility of using thermography to visualize sinusitis. Methods In the present study, heat distribution on the faces of individuals with and without sinusitis was studied using thermography. Overall, 10 control subjects and 20 patients with sinusitis were included. Original thermography data were cropped, resized, and converted to relative thermography data based on the average temperature for visualization and statistical analysis. Results The shape of the maxillary and/or frontal sinuses was determined based on regions indicating increased temperature in patients with sinusitis. The region with increasing temperature was statistically visualized, and the significant side (t test, p < 0.05) coincided with the maxillary shadow on X-ray imaging. Conclusion Thermography demonstrates visually the correlation between the surface temperature of the face and inflammation patterns in the paranasal sinus. Therefore, our comparative study using thermography to visually differentiate individuals with and without sinusitis was effective, indicating that thermography is a possible alternative to X-ray imaging to detect sinusitis.