Thyroidectomy, due to malignancy, is usually followed by radioiodine ablation in order to treat residual or metastatic disease and ablate remnant thyroid tissue. The aim of this study was to investigate changes in patients’ health-related quality of life (HRQoL) before and after radioiodine ablation (RAI) and identify patients’ characteristics related. We conducted a cross-sectional study of 85 patients aged 20–82 years old who had recently underwent near total thyroidectomy due to papillary-follicular thyroid cancer and were hospitalized in the Iodine Unit of a major hospital to receive RAI. HRQoL was estimated by 36-Item Short-Form Health Survey (SF-36) at three time points as follows: on the first day of their hospitalization, 3 months after treatment, and 1 year after treatment. Consistent with the previous literature, the results of this study revealed that HRQoL in DTC patients is independent with the majority of the variables examined. All SF-36 scales were significantly improved both times measured post Iodine-131 (131I) administration in comparison with scores prior to RAI (p