[en] Background: The aim of this study is to evaluate the therapeutic success rate and serum thyroglobulin change after 131I ablation therapy in patients with differentiated thyroid carcinoma post-total thyroidectomy. Methodology: Thirty four patients with differentiated thyroid carcinoma post-total thyroidectomy treated with low-dose 131I ablation therapy (32 patients with 30 mCi and 2 patients with 60 mCi) between March 2011 and April 2014 were involved in this retrospective study. The imaging results of 131I whole body scintigraphy and the change of serum thyroglobulin before and six months after therapy were analysed. Results: Twenty seven (79%) out of 34 patients were found to have no thyroid uptake on their 131I whole body scintigraphy image after 131I ablation therapy and six months later. 7 patients (21%) were found to have thyroid uptake on their WBS. Serum thyroglobulin had significantly decreased from the time of treatment to six months follow up (Wilcoxon Signed Rank Test P < 0.001). Serum thyroglobulin was significantly decreased in successful cases (N = 27, Wilcoxon Signed Rank Test P < 0.01,). There was no significant decrease of serum thyroglobulin in unsuccessful cases (N=7, Wilcoxon Signed Rank Test P=0.612) Conclusion: Our findings suggest that low therapeutic dose of 131I is useful for the ablation of differentiated thyroid carcinoma post-total thyroidectomy, with the success rate of 79%. High serum thyroblobulin level group is unlikely to be successful and needs a higher dose of 131I. (author)