Phlegmons are unencapsulated collections of inflammation that track along soft tissues in various parts of the human body. These soft-tissue lesions are uncommon in the lower extremities and can be difficult to identify and treat. This article presents a case of a plantar foot phlegmon in a nondiabetic patient that was recalcitrant to debridement and antibiotics. The patient's aseptic phlegmon completely resolved with surgical debridement and iodoform packing. This case report demonstrates the role of advanced imaging in the diagnosis of lower-extremity phlegmons and the importance of thorough surgical debridement and packing for successful resolution.