Objective To investigate the value of neutrophil to lymphocyte ratio (NLR) in predicting in-stent restenosis (ISR) in patients with coronary heart disease. Methods We collected the data of 618 patients with coronary heart disease hospitalized in the Department of Cardiology in the First Affiliated Hospital of Kunming Medical University from January 2011 to June 2012. All selected patients underwent coronary angiography and stent implantation, and were divided into two groups according to the average size of NLR. The relationship between the neutrophil to lymphocyte ratio and coronary heart disease in-stent restenosis was investigated. Results There were statistically significant differences in the presence of diabetes, high density lipoprotein, low density lipoprotein, the percentage of neutrophils and lymphocytes in patients between two groups (P<0.05) . We found 13 patients (4.2%) and 32 patients (10.4%) with in-stent restenosis in the first group and the second group, respectively, and there was a statistically significant difference between two groups (P<0.01) . Conclusion Neutrophil to lymphocyte ratio is correlated with ISR,and has clinical value in predicting ISR.