PURPOSE: We investigated the prognosis according to age in papillary thyroid carcinoma (PTC) patients. METHODS: We retrospectively evaluated 2,890 patients who underwent thyroidectomy due to PTC between May 2004 and Aug 2008. We divided patients into 3 groups: young (< or =35 years old), middle (between 35 and 54 years old), and old (> or =55 years old). RESULTS: Median age was 47.0 years old (range, 15 to 82 years). Within a follow-up period median of 50 months, there were 148 (5.1%) locoregional recurrences, 6 (0.2%) PTC-related deaths, and 18 (0.6%) PTC-unrelated deaths. Outcomes were more favorable in the young group, with no PTC-related death despite the frequent locoregional recurrence. In the old group compared to the middle, there was a higher proportion of male, and more aggressive types as T3 or N1b, higher mean tumor number, more multiplicity, and bilaterality. The old group of > or =55 years did not show a significant difference in PTC-related deaths than other age groups in Cox analysis (OR, 0.9; P = 0.677), but a significant cutoff age in PTC-related deaths at 62.5 years was determined in ROC analysis (area under curve = 0.912). CONCLUSION: We showed that the < or =35 years group shows favorable prognosis despite the frequent locoregional recurrence and > or =62.5 years group shows a poor prognosis regardless of other factors such as male sex or tumor aggressiveness. Further multiinstitutional studies are needed to elucidate the prognosis according to patient's age.