The role of triglycerides (TG) in coronavirus disease (COVID-19) is controversial. The objective of this study was to explore the relationship between TG levels and prognosis in COVID-19 patients and investigate the factors that affect TG. COVID-19 patients were divided into normal or high TG level groups. Their demographic data, medical history, signs and symptoms, laboratory results, and final clinical results were analyzed retrospectively. A total of 174 patients were included. TG level was 1.6 (interquartile range [IQR]: 1.1-2.1) mmol/L for all patients; 2.2 (IQR: 1.8-2.7) mmol/L and 1.1 (IQR: 1.0-1.3) mmol/L in the high TG and control groups, respectively. Overall, 29 patients (16.7%) died during hospitalization, including 19 (23.1%) in the high TG group and 10 (11.5%) in the control group (absolute survival difference, 2.5% (95% confidence interval [CI], 1.2%-5.1%), log-rank chi(2) = 5.7, and p = .017). Serum ferritin, C-reactive protein (CRP), lactate dehydrogenase (LDH), and interleukin-10 (IL-10) levels were significantly higher in the high TG group compared to the control group. Pearson correlation analysis showed that TG was positively correlated with fasting blood glucose, leukocyte, serum ferritin, LDH, CRP, and IL-10 levels. Multiple regression showed that serum ferritin and IL-10 levels affected the TG level (R-2 = .095). The TG level in COVID-19 patients is correlated to serum ferritin and IL-10 levels, which reflects the activation of macrophages. It is suggested that COVID-19 patients be monitored for elevated TG as both a prognostic indicator and potential therapeutic target for COVID-19.