Background <p>Risk factors associated with postoperative pulmonary complications (PPCs) in bronchiectasis patients undergoing non-cardiothoracic surgery are not well understood. This study aimed to identify perioperative risk factors for PPCs in bronchiectasis patients undergoing non-cardiothoracic surgery, with particular attention to the relationship between preoperative lung function and complication risk.</p> Methods <p>This single-center retrospective study analyzed patients with bronchiectasis who underwent non-cardiothoracic surgery between January 2021 and August 2024. Multivariable logistic regression was used to identify independent risk factors for PPC development. Restricted cubic spline analysis was performed to evaluate non-linear associations between continuous pulmonary function parameters and PPC risk.</p> Results <p>Of 275 patients with bronchiectasis, 49 (17.8%) developed PPCs. Multivariable analysis identified three risk factors associated with PPCs: lower preoperative FEV₁ (% predicted) (Odds ratio [OR] = 0.97 per 1% increase; 95% confidence interval [CI], 0.96–0.99; <i>p</i> = 0.003), abdominal surgery (open and laparoscopic) (OR = 4.14; 95% CI, 1.68–10.23; <i>p</i> = 0.002) and prolonged operative duration (OR = 2.38 per hour; 95% CI, 1.73–3.27; <i>p</i> &lt; 0.001). Restricted cubic spline analysis revealed a significant nonlinear relationship between preoperative FEV₁ (% predicted) and risk of PPCs in adjusted models (<i>p</i> = 0.008). Patients with FEV₁ ≤ 50% predicted demonstrated a 3.27-fold increased odds of PPCs compared to those with normal lung function (FEV₁ &gt; 80% predicted), with the risk being even higher at FEV₁ ≤ 30% predicted.</p> Conclusions <p>Among bronchiectasis patients undergoing non-cardiothoracic surgery, decreased preoperative FEV₁, abdominal surgery, and prolonged operative time were identified as independent risk factors for PPC occurrence.</p>