Objective: Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) remains a major challenge in interventional cardiology. The exact toxic components of cigarette smoke and the mechanisms involved in smoking-related cardiovascular dysfunction are largely unknown, but it increases inflammation, thrombosis, and oxidation of low-density lipoprotein cholesterol. There is only insignificant knowledge reported in the literature about the influence of smoking habits on acute outcome in CTO PCI. Methods: Between 2012 and 2017, a total of 559 patients were included in the study. The patients all underwent PCI for at least 1 CTO. Antegrade and retrograde CTO techniques were applied. The Shapiro-Wilk test was used to test for normality of distribution. Continuous variables were tested for differences with the Kruskal–Wallis test or the Mann–Whitney U test, as appropriate. Categorical variables were tested using Fisher's exact test. Results: Non-smokers were older than smoking patients (65.3+-10.3 years vs. 58.3+-9.2 years; p