Objective: The aim of this study is to use stroke volume variation (SVV) as an indicator to predict fluid responsiveness in patients undergoing protective one‑lung ventilation (OLV) in pressure‑controlled ventilation mode. Design and Setting: A prospective clinical study in an operating room in a medical center. Patients: Fourteen patients receiving video‑assisted thoracic surgery while undergoing OLV in pressure‑controlled ventilation mode. Methods: After starting OLV in pressure‑controlled ventilation mode, all patients were administered 6 ml/kg 6% hydroxyethyl starch for 20 min. Vigileo‑FloTrac system was used to record hemodynamic variables before and after volume loading. The ability of SVV to predict fluid responsiveness was tested by calculating the area under the receiver operating characteristic (ROC) curve for an increase in stroke volume index of ≥10% after volume loading, and the optimal threshold value of SVV was calculated. Results: The area under the ROC curve for SVV to discriminate between responders and nonresponders was 0.89 (95% confidence interval, 0.700–1; P = 0.03). The optimal threshold value of SVV was 8.5% (sensitivity 88.89%; specificity 75%). Conclusions: SVV may be suitable for predicting fluid responsiveness in patients undergoing protective OLV in pressure‑controlled ventilation mode.