BACKGROUND: Shared decision-making (SDM) has been linked to important health care quality outcomes. However, to the authors' knowledge, the value of SDM has not been thoroughly evaluated in the field of radiation oncology. The objective of the current study was to determine the association between SDM and patient satisfaction during radiotherapy (RT). The authors also explored patient desire for and perception of control during RT, and how these factors relate to patient satisfaction, anxiety, depression, and fatigue. METHODS: A cross-sectional survey of 305 patients undergoing definitive RT was conducted. Patients self-reported measured variables during the last week of RT. Relationships between variables were evaluated using chi-square analyses. RESULTS: Among study participants, 31.3% of patients experienced SDM, 32.3% perceived control in treatment decisions, and 76.2% reported feeling very satisfied with their care. Patient satisfaction was associated with perceived SDM (84.4% vs 71.4%; P <.02) and patient-perceived control (89.7% vs 69.2%; P <.001). Furthermore, the perception of having control in treatment decisions was associated with increased satisfaction regardless of whether the patient desired control. Increased anxiety (44.0% vs 20.0%; P <.02), depression (44.0% vs 15.0%; P <.01), and fatigue (68.0% vs 32.9%; P <.01) were reported in patients who desired but did not perceive control over their treatments, compared with those who both desired and perceived control. CONCLUSIONS: The findings of the current study emphasize the value of SDM and patient-perceived control during RT, particularly as it relates to patient satisfaction and psychological distress. Regardless of a patient's desire for control, it is important to engage patients in the decision-making process.