We assessed the association between neutrophil to lymphocyte ratio (NLR) and chronic coronary total occlusion (CTO), as well as clinical prognosis of percutaneous coronary intervention (PCI). Patients referred for elective coronary angiography for stable angina pectoris were enrolled, including a CTO (n = 160) and a non-CTO group (n = 160). Neutrophil to lymphocyte ratio on admission and post-PCI was measured, and NLR was defined as the change between the 2 values. Subgroup analysis was performed based on the value of NLR (≥0.5 vs <0.5). Clinical characteristics, angiographic data, and follow-up data were recorded. Compared with the non-CTO group, the total white blood cell count, neutrophil counts, and NLR were significantly higher in the CTO group. In the NLR ≥ 0.5 subgroup, the incidence of severe dissection, slow coronary flow, in-stent restenosis (ISR), and major adverse cardiac events (MACEs) was obviously higher. In multivariate analysis, NLR was independently and positively associated with higher risks of ISR and MACE. The NLR could be a potential predictor of CTO, and NLR is independently associated with the adverse clinical outcomes in patients who underwent PCI.