Eighty-three autopsy cases of squamous cell carcinoma of the oral tongue were reviewed to identify retrospectively the causes of treatment failure. The cure rate for the primary cancers at autopsy was 48.2% (40 of 83). Regional lymph node metastases were found in 71.1% (59 of 83). Regional metastases and/or juxtaprimary recurrence frequently spread continuously and diffusely, forming bulky neck tumors in 38.6% (32 of 83). The incidence of distant lymph node metastasis (below the clavicle) and hematogenous metastasis was 35.4% (29 of 82) and 58.5% (48 of 82), respectively. The lung was the most common site of hematogenous metastases (52.4%, 43 of 82). Hematogenous metastasis occurred more frequently in the younger age group (< 40 years of age; P = 0.03). Distant lymph node metastases were identified in the lung hilar, bifurcation, and paratracheal nodes in 89.7% (26 of 29) and had a statistically significant association with lung hematogenous metastasis. Univariate analysis revealed that gross appearance, tumor stage, clinical stage, presence of cervical lymph node metastasis, and interval from NO to NX were significant predictors of survival time (duration from initial treatment to death). Rupture of the neck vessels was fatal in eight patients (9.6%), and hypercalcemia was seen in six (7.2%). Pulmonary infection was the direct cause of death in 33.7% of patients (28 of 83). Secondary malignant lesions occurred in 22.9% (19 of 83).