Abstract Background Adenosquamous carcinoma (ASC) of the head and neck is a rare malignancy characterized by loco-regional and distant aggressiveness. At histology, ASC reveals two distinct, juxtaposed components, squamous cell carcinoma (SCC), and true adenocarcinoma. Methods The immunohistochemical expression of AE3, CK19 and CAM5.2, and HPV infection was tested in a case of laryngeal ASC. Results The patient had no regional lymph node metastases, but developed a recurrence in neck soft tissues shortly after primary radical surgery. The laryngeal surgical specimen had the typical morphological features of ASC. The tumor's squamous and glandular components were both strongly and diffusely immunoreactive for AE3 and CK19, whereas CAM5.2 selectively stained only the gland-like part. We found no high- or low-risk HPV DNA (28 genotypes) in the specimens. The patient underwent salvage extended radical neck dissection and received postoperative radio-chemotherapy. At 4-month follow-up control, neck recurrence was found. Palliative chemotherapy was instituted. Conclusions An accurate histological and immunohistochemical diagnosis is mandatory to differentiate ASC from conventional SCC. Radical surgical excision is recommended for laryngeal ASC. Adjuvant postoperative therapy is administered in most cases, but there are no widely accepted indications for these treatments.