Objective To investigate the clinical features of patients with cardiac amyloidosis and the factors affecting their long-term prognosis. Methods A retrospective study was conducted of 119 patients with clinically diagnosed cardiac amyloidosis by reviewing their clinical data, and survival obtained from follow-up telephone. Analysis was made of their clinical manifestations, electrocardiogram, echocardiogram and cardiovascular magnetic resonance and of their relationship with long-term prognosis, the primary end-point being all-cause mortality. SPSS statistics 17.0 was employed for data analysis. Results Symptoms of the 119 patients varied widely, featuring mainly shortness of breath and chest tightness followed by edema of lower limbs and fatigue. Cardiac function was mostly New York Heart Association (NYHA) Ⅲ-Ⅳ class. One-year mortality rate was 50%, and five-year mortality rate was 25%. Independent factors affecting all-cause deaths included N-terminal pro-brain natriuretic peptide (NT-proBNP), troponin T, carbohydrate antigen 125 (CA125), albumin, blood chloride, and immunoglobulin M (IgM). Conclusion Prognosis of cardiac amyloidosis is poor with a 1-year survival rate of only 50%. Independent factors affecting all-cause deaths include NT-proBNP, troponin T, CA125, serum albumin, blood chloride, and serum IgM.