Objective <p>Clinically, coronary artery stenosis exceeding 50% can be diagnosed as coronary heart disease (CHD), and its relationship with inflammatory factors remains unclear. This study aimed to detect the contents of NLRP3 and its downstream inflammatory factors (IL-1 β and IL-18) in the plasma of patients with different types of CHD and evaluate its correlation with the severity of CHD.</p> Methods <p>Ninety patients with chest tightness and chest pain were included. They were divided into three groups according to the findings from medical history and coronary angiography: normal control group (N group), stable angina group (SA group), and acute coronary syndrome group (ACS group) (<i>n</i> = 30 per group). ELISA was used to determine the contents of NLRP3 inflammasome, IL-1β and IL-18 in the plasma. The CHD patients were scored with Gensini scoring system. Pearson correlation analysis was employed to evaluate the correlation of NLRP3, IL-1β and IL-18 with Gensini score in these patients.</p> Results <p>As compared with the control group, patients in the ACS and SA groups had markedly elevated plasma levels of NLRP3, IL-1β and IL-18. As compared to the SA group, the Gensini score and plasma levels of NLRP3, IL-1 β, IL-18 significantly increased in the ACS group. Pearson correlation analysis showed that the Gensini score was positively related to plasma levels of NLRP3, IL-1β and IL-18 in patients with CHD.</p> Conclusion <p>Elevated plasma levels of NLRP3, IL-1β and IL-18 in CHD patients may be closely related to the stability of coronary plaques and the severity of coronary lesions, and may aid the diagnosis of CHD and assessment of CHD severity.</p>