Radioactive iodine remnant ablation (RRA) is used to destroy residual normal thyroid tissue after complete gross surgical resection of papillary or follicular thyroid cancer. The article updates a prior systematic review of the literature to determine whether RRA decreases the risk of thyroid cancer-related death or recurrence at 10 years after initial surgery, including data from 28 studies. No long-term randomized trials were identified, so the review is limited to observational studies. The incremental benefit of RRA in low risk patients with well-differentiated thyroid cancer after total or near-total thyroidectomy who are receiving thyroid hormone suppressive therapy remains unclear.