BackgroundInsulin resistance (IR) plays a vital role in the pathogenesis of Type 2 Diabetes Mellitus (T2DM). The mechanism of IR may be associated with inflammation, whereas the neutrophil-lymphocyte ratio (NLR) is a new indicator of subclinical inflammation. Scholars have rarely investigated the relationship between IR and NLR. This study aims to evaluate the relationship between IR and NLR, and determine whether or not NLR is a reliable marker for IR.MethodsThe sample consists of a total of 413 patients with T2DM, 310 of whom have a HOMA-IR value of > 2.0. The control group consists of 130 age and BMI matched healthy subjects.ResultsThe NLR values of the diabetic patients were significantly higher than those of the healthy control (P < 0.001), and the NLR values of the patients with a HOMA-IR value of > 2.0 are notably greater than those of the patients with a HOMA-IR value of ≤ 2.0 (P < 0.001). Pearson correlation analysis showed a significant positive correlation of NLR with HOMA-IR (r = 0.285) (P < 0.001). Logistic regression analysis showed that the risk predictors of IR include NLR, TG and HbA1c. NLR (P < 0.001, EXP(B) = 7.231, 95% CI = 4.277–12.223) levels correlated positively with IR. The IR odds ratio increased by a factor of 7.231 (95% CI, 4.277–12.223) for every one unit increase in NLR.ConclusionsIncreased NLR was significantly associated with IR, and high NLR values may be a reliable predictive marker of IR.Electronic supplementary materialThe online version of this article (doi:10.1186/s12902-015-0002-9) contains supplementary material, which is available to authorized users.