Eustachian tube dilation (ETD) is a relatively new intervention for the treatment of eustachian tube dysfunction. Though it previously had no assigned billing code, the American Medical Association recently accepted a new Category I Current Procedural Terminology code application for ETD to be effective in January 2021. Reported complications are uncommon and usually minor. Herein, we present a rare case of massive pneumomediastinum following this procedure. Such major complications are critical to report as ETD becomes a more commonly practiced procedure.