Cardiac lipomatous hypertrophy is a rare benign condition almost exclusively involving the interatrial septum. Interventricular septum involvement is seldom noted, with only a few documented case reports demonstrating the finding on various modalities such as ECHO, CT, and MRI. FDG PET can be a surrogate marker for lipomatous hypertrophy of the interventricular septum. Here, we describe a case of incidentally detected lipomatous hypertrophy of the interventricular septum on FDG PET/CT in a patient with squamous cell carcinoma of the oropharynx.