Chronic heart failure (CHF) is a complicated syndrome caused by structural and functional abnormalities. Long noncoding RNA (LncRNA) lung cancer-associated transcript 1 (LUCAT1) downregulation inhibits cardiomyocyte apoptosis. This study aimed to measure LUCAT1 expression in patients with CHF and to explore its clinical value on CHF diagnosis and prognosis. A total of 94 patients with CHF and 90 participants without CHF were registered, followed by recording of their clinical characteristics and grading of their cardiac function. LUCAT1 expression in sera of patients with CHF and participants without CHF was detected. The correlation of LUCAT1 with brain natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) in patients with CHF and the diagnostic efficiency of LUCAT1, BNP, and LUCAT1 combined with BNP on patients with CHF were analyzed. Patients with CHF were treated with conventional drugs and followed up. The LUCAT1 expression in patients with CHF was lower than that in participants without CHF and was downregulated with the increase of New York Heart Association stage. LUCAT1 expression was negatively associated with BNP but positively associated with LVEF in the sera of patients with CHF. The receiver operating characteristic curve of LUCAT1 combined with BNP had better result than that of LUCAT1 and BNP alone. Low LUCAT1 expression indicated poor prognosis of patients with CHF and was an independent prognostic factor for the survival of patients with CHF. To summarize, low lncRNA LUCAT1 expression might help diagnose and predict the poor prognosis of CHF.