Background: Pressure ulcers are a common and challenging problem affecting bed-ridden patients. Flap operations are considered a surgical option for treating pressure sores despite their high rate of complications and recurrence. Hypothesizing that certain factors would af-fect postoperative outcomes for pressure sore patients, we analyzed the factors and outcomes. Methods: We collected cases retrospectively from January 2010 to January 2018. The subjects were 95 patients who had undergone flap operation in our institution. Patient demographics, wound characteristics, and outcomes including relapses, flap complications, reopera-tion, and newly developed sores were analyzed. Logistic regression analysis was used to identify the association between variables and surgical outcomes. Results: Patients who had larger area of defects after debridement had more flap complications (P=0.01) and were more likely to undergo reoperation (P=0.03). Smokers (P=0.04) and patients whose wound cultures were positive (P=0.04) had more flap complications. Patients who had paralysis were more likely to require reoperation (P=0.02) and to develop new sores (P=0.02). Conclusion: We identified factors affecting postoperative outcomes after flap operation to cover pressure sores. As a more comprehensive preoperative risk assessment on flap reconstruction for pressure sores can improve outcomes, these indicators should be carefully considered when determining surgical options.