Our aim was to investigate the association between the triglycerides/glucose index (TyG index) and the homeostasis model assessment-estimated insulin resistance (HOMA-IR) in the prediction of insulin resistance (IR) among adolescents. We conducted a cross-sectional study among 221 Korean adolescents (168 males and 53 females aged 9-13 years) from May to June 2014 in Chung-ju city. The TyG index was calculated as ln triglycerides (mg dl ) × fasting glucose (mg dl )/2. IR was defined using HOMA-IR >95th percentile for age and sex. In the IR group, weight, body mass index (BMI), waist circumference, body fat, fasting insulin, fasting plasma glucose, triglyceride levels and triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) were significantly higher than that in the non-IR group. The TG index was significantly different between the IR group (n=22) and non-IR group (n=199), at 8.43±0.45 and 8.05±0.41, respectively (P<0.001). The TyG index was well correlated with HOMA-IR (r=0.41; P<0.001) and showed a strong positive association with TG/HDL-C (r=0.84; P<0.001). The cut-off of the TyG index for diagnosis of insulin resistance was 8.18. The TyG index is a simple, cost-effective surrogate marker of insulin resistance among adolescents compared with HOMA-IR.