Ludwig’s angina is a serious and potentially life-threatening phlegmon of the floor of the mouth and neck requiring prompt diagnosis and treatment. Diffuse infection in Ludwig’s angina can rapidly spread to surrounding tissues and potentially lead to serious complications such as aspiration pneumonia, sepsis, or airway obstruction. The condition is commonly caused by polymicrobial infections of odontogenic origin, as presented in this case. A 60-year-old male was admitted to the emergency department with massive swelling of the left side of the face and neck, lasting 2 weeks. Intraoral examination revealed multiple carious lesions and purulent drainage. Computed tomography of the neck and craniofacial area showed a diffuse phlegmon extending from the oral cavity floor to the subcutaneous and deep tissue of the neck with involvement of the left parotid gland. Extensive caries of teeth 33 and 34 were suggested to be the starting point of the infection. Emergency surgical drainage and debridement with tooth extraction were performed under general anesthesia, and empirical antibiotic therapy was started. Computed tomography on the second postoperative day revealed a significantly increased extent of the infection that required further surgical debridement. Following the results of microbiological culture and sensitivity testing, the antibiotics were changed, and standard wound and drain care was continued. The patient improved significantly and was released 18 days after admission. This case highlights the importance of prompt and aggressive management of Ludwig’s angina to prevent severe complications and optimize patient outcomes.