Objective: To assess functional outcomes in patients treated by compartmental tongue surgery (CTS) and reconstruction for advanced oral tongue/floor-of-mouth cancer. Study Design: Retrospective case series. Methods: A retrospective cohort of patients (n = 48) treated by CTS and free flap reconstruction was prospectively evaluated concerning postoperative functional outcomes at different time points (6 months and 1 year). Swallowing was studied by videonasal endoscopic evaluation (VEES) and videofluoroscopy (VFS), testing various food consistencies and grading the results with the Donzelli scale. Speech articulation, lingual strength, and endurance were studied by phone call and Iowa Oral Performance Instrument (IOPI). Subjective tests (EORTC H&N35 and UWQOL) were administered. Results: After 1 year, VEES showed a Donzelli scale of 67% level 1, 23% level 2, and 10% level 3. Vallecular pouch was present in 81% of patients. VFS showed levels 1, 2, and 3 in 42%, 25%, and 33%, respectively, with liquids (L); 48%, 19%, and 33%, with semi-liquids (SL); and 54%, 33%, and 13%, with semi-solids (SS). Vallecular pouch residue was present in 69% with L, 73% with SL, and 87% with SS. The mean number of words recognized at phone call was 56 of 75 (range, 27-74). IOPI showed a mean tongue strength of 19.2 kPa (range, 0-40), and a mean endurance of 16.2 seconds (range, 0-60). Conclusion: CTS does not significantly affect speech. Sub-clinical food aspiration and vallecular pouch are present in a significant proportion of patients, especially when adjuvant treatments are administered. Residual tongue strength is not affected when proper reconstruction is performed.