This study was performed to report the outcomes of patients with oral squamous cell carcinoma (OSCC) of the tongue over a 10-year period with the aim of testing the hypothesis that the lymph node ratio (LNR) has a significant influence on loco-regional recurrence. The charts of 227 patients with OSCC of the mobile tongue treated at the University Hospital of Zurich from 2003 to 2012 were screened. Following the application of the exclusion criteria (prior chemotherapy, radiotherapy, or surgery, perioperative death, N3 disease, unresectable disease, synchronous second primary, no signed informed consent, and follow-up <3years), prospective data were collected and a retrospective analysis performed for 88 of these patients who were treated with selective neck dissection. During a mean follow-up period of 78 months (standard deviation 37 months), loco-regional recurrence was diagnosed in 25 patients (28%). The overall and disease-specific survival rates for the study population were 72% and 80%, respectively. Perineural invasion was identified as an independent risk factor for decreased disease-specific survival, whereas LNR was not. LNR did not show an influence on disease recurrence. Thus, its prognostic value in patients with tongue cancer remains uncertain and the decision regarding adjuvant therapy should not be made solely on the basis of LNR.