Objective To evaluate the relationship between serum procalcitonin (PCT) elevation and clinical characteristics and prognosis of patients with acute attack of chronic heart failure(CHF) but without clear evidence of bacterial infection. Methods Patients with acute attack of CHF and hospitalized in Handan Central Hospital from February 2015 to December 2017 were studied prospectively. According to PCT level, patients were divided into elevated PCT group and normal PCT group, basic clinical characteristics of two groups of patients were compared, causes of PCT elevation were analyzed by logistic regression; efficacy of standard treatment 48 hours after admission and the incidence of all-cause death/readmission within 30 days were compared. Results A total of 593 patients with acute attack of CHF were enrolled, including 521 patients with normal PCT and 72 patients with elevated PCT. Logistic regression analysis showed that the increase of heart rate, pulmonary edema, white blood cell count(WBC) and blood urea nitrogen (BUN) were positively correlated with the elevation of PCT, especially WBC (OR, 2.19[95% CI, 1.76-2.73], P<0.001); hemoglobin and serum albumin were negatively correlated with PCT elevation. After 48 hours of standardized treatment, symptoms of 67.9% of patients in normal PCT group significantly improved, which was higher than 55.6% in elevated PCT group (P=0.037). The 30-day all-cause mortality/readmission rate in patients in elevated PCT group was higher than that in normal PCT group (30.6% VS 18.8%), difference was statistically significant (P=0.02). Conclusion Although the degree of heart failure is the same, patients with acute attack of CHF and elevated serum PCT level have poor therapeutic effect and poor prognosis, suggesting that there may be undiagnosis or potential bacterial infection.