Little is known about how patients' emotions impact the choice between hemi- and total thyroidectomy (TT) for low-risk thyroid cancer (LR-TC) and how these emotions change after treatment. To investigate thyroid cancer-specific fear and worry both before and after treatment of LR-TC with hemi- or TT. This prospective cohort study enrolled adults with confirmed or likely LR-TC at 15 institutions. Participants completed measures of thyroid cancer-related fear and worry at the time of their treatment decision and 9-months later. Participants were categorized as having low, medium, or high levels of fear and worry in accordance with the literature. Those choosing hemi-thyroidectomy were compared to those choosing TT. Of 177eligible patients, 125 (70.6%) enrolled and 114 completed both surveys (91.2% retention). Overall, 41 (36.0%) participants chose hemi-thyroidectomy and 73 (64.0%) chose TT. Across all participants, thyroid cancer-related fear and worry both decreased significantly after surgery (fear 25.8±6.4 to 23.1±7.4; worry 8.2±2.4 to 5.4±2.1, p<0.001). The proportion of participants with high fear decreased from 64.9% to 50.9%, while the proportion with high worry decreased from 75.4% to 41.2% (p<0.001 for both). At both time points, no differences existed between those choosing hemi- and TT in levels of worry or fear. Patients with LR-TC report lower levels of fear and worry 9-months after surgery regardless of the extent of surgery, suggesting that both surgeries provide an emotional benefit to some patients. Thyroid cancer-related fear and worry do not appear to influence patients' decisions to undergo hemi- or TT.