<p>Smoking is a significant risk factor for postoperative complications, including cardiovascular, pulmonary, and wound-related issues. Pre-operative smoking cessation is widely recommended to mitigate these risks, but the effectiveness of different interventions remains uncertain. This study aims to evaluate the effectiveness of pre-operative smoking cessation interventions in reducing smoking rates and postoperative complications across various surgical settings. A comprehensive search was conducted across databases including Medline/PubMed, Embase, CINAHL, And CENTRAL, up to July 2024, following PRISMA guidelines. Randomized controlled trials (RCTs) assessing the effectiveness of pre-operative smoking cessation interventions were included. Data were extracted on intervention types, smoking cessation outcomes, and postoperative complications. The Cochrane Collaboration tool was used to assess the risk of bias, and a random-effects meta-analysis was performed to pool the results. Certainty of evidence was assessed using the GRADE approach. Out of 9,188 studies identified, 24 met the inclusion criteria, encompassing 4,763 patients. The pooled analysis revealed that pre-operative smoking cessation interventions probably increase the likelihood of smoking cessation before surgery (RR = 1.98, 95% CI: 1.53–2.56; moderate-certainty evidence), although there was heterogeneity among the studies (I²= 83.30%). Additionally, these interventions probably reduce overall postoperative complications by 27% (RR = 0.73, 95% CI: 0.58–0.94; moderate-certainty evidence), with moderate heterogeneity (I² = 49.06%). However, they may have a non-significant impact on wound-related complications (RR = 0.63, 95% CI: 0.33–1.20; low-certainty evidence). Preoperative smoking cessation interventions probably increase short-term abstinence and likely to reduce the risk of overall postoperative complications. However, their impact on wound-related complications may be limited and remains uncertain.</p>