Inflammation plays a central role in the pathogenesis of acute coronary syndromes, the prevalence of which is increased in individuals with diabetes. Monocytes and macrophages, T cells and mast cells contribute to the initiation, development and rupture of atherosclerotic plaques by synthesising a variety of pro-inflammatory cytokines, including interleukin 1β, interleukin 6 and tumour necrosis factor a. Cytokines upregulate endothelial cell adhesion molecules, recruit leukocytes and induce smooth muscle cell migration and proliferation. Cytokines act systemically to initiate the acute phase response, up-regulating proteins involved in inflammation and haemostasis and resulting in a pro-inflammatory and pro-thrombotic state. Expression of tissue factor by inflammatory cells potently induces thrombus formation upon plaque rupture, leading to acute coronary syndromes. Inflammatory biomarkers, including C-reactive protein, complement proteins, interleukin 6 and white blood cell count, predict development of acute coronary syndromes. C-reactive protein has been widely studied and consistently predicts future acute coronary syndrome events.