This study evaluated the association between high-sensitivity C-reactive protein (hsCRP) and metabolic syndrome, defined by the definition proposed by the International Diabetes Federation (IDF), American Heart Association (AHA) and National Heart, Lung, and Blood Institute (NHLBI) versus the older IDF definition, in 506 Chinese patients with type 2 diabetes. Anthropometric and biochemical parameters were compared and analysed using multivariate linear regression models. Serum hsCRP was higher in patients with metabolic syndrome compared with those without metabolic syndrome for both definitions and increased as the number of components of metabolic syndrome increased (after adjusting for age, gender and smoking). Patients with metabolic syndrome according to the IDF/AHA/NHLBI but not the IDF definition had significantly higher hsCRP levels than those not meeting either definition and similar hsCRP levels to those meeting both definitions. Serum hsCRP levels were significantly associated with metabolic syndrome according to the IDF definition after adjusting for age, gender and smoking. Adding metabolic syndrome status according to the IDF/AHA/NHLBI definition significantly increased the fit of the multivariate linear regression model. The new IDF/AHA/NHLBI definition of metabolic syndrome may have a stronger relationship with serum hsCRP than the IDF definition.