Purpose <p>Frailty is increasingly recognized as a risk factor for surgical complications; however, its association with postoperative pulmonary complications (PPCs) following pulmonary resection remains controversial. This study aimed to systematically evaluate the association between frailty and PPCs in elderly patients undergoing pulmonary resection.</p> Methods <p>We systematically searched PubMed, Cochrane Library, Embase, CNKI (China National Knowledge Infrastructure), CBM (China Biology Medicine Disc) , Wanfang Database, Cochrane Central Register of Controlled Trials, and Web of Science from inception to April 2024, using the search terms: (frailty OR frail) AND (pneumonectomy OR lobectomy OR lung resection OR lung cancer). Two investigators independently screened literature, extracted data, and assessed risk of bias. Statistical analyses were performed using Review Manager version 5.4.</p> Results <p>Twelve observational studies involving 394,947 patients were included. Frailty was significantly linked to PPCs risk (odds ratio [OR] = 2.96, 95% confidence interval [CI]: 2.15–4.06, <i>I</i>^<i>2</i> = 97%). Subgroup analysis indicated that the mFI-11 scale demonstrated a potentially strong predictive value (OR = 3.47, 95% CI: 2.04–5.92, <i>I</i>^<i>2</i> = 59%), though this requires validation in larger prospective cohorts.</p> Conclusion <p>Frailty is independently associated with an increased risk of PPCs in elderly patients undergoing pulmonary resection.</p> Systematic review registration <p>PROSPERO (Prospective Register of Systematic Reviews), registration ID: CRD42024532270.</p>