Objectives : Ablation of carcinoma of the tongue leads to deficits in speech and swallowing, but none to date has provided all of the qualities of mobility and sensation to simulate the complex function of the tongue. The authors evaluated postoperative swallowing and pronouncing function in patients who underwent tongue reconstruction using free flap. Material and Methods : This is a retrospective review documenting the outcome of 42 patients between January of 1991 and August of 2008. We classified patients according to the size of resection of the tongue like as 7 partial glossectomy, 25 hemiglossectomy, 2 subtotal glossectomy, and 8 total glossectomy. Swallowing function was graded into 4 point scale and pronouncing function was analyzed using picture consonant articulation test. Aspiration was evaluated with videofluoroscopic swallowing study. Results : The average points for swallowing function were 3.43 in partial glossectomy, 3.52 in hemiglossectomy, 3 in subtotal glossectomy, and 2.63 in total glossectomy. The percentage of consonants correct showed 76.5% in partial glossectomy, 72.29% in hemiglossectomy, 47.69% in subtotal glossectomy, and 29.94% in total glossectomy. Aspiration was noted in 3 patients(1 hemiglossectomy and 2 total glossectomy) and 2 total glossectomy patients were taken permanent feeding gastrostomy. Conclusion : Free flap gave us proper volume in tongue reconstruction and showed good result in preserving swallowing function. Swallowing function difference according to the size of defect showed no statistical significance, whereas articulation function was shown to decrease in accuracy as the size of defect was larger.