Ethnopharmacological relevance: Lianhuaqingwen (LHQW) is a Chinese medicine, developed from appropriate addition and reduction of combined traditional Chinese medicine (TCM) Yinqiao San and Maxing Shigan decoction. LHQW has been used in routine influenza treatment for decades and plays a role in a broad-spectrum therapy on various influenza viruses. Aims of the study: The therapeutic effects of LHQW in coronavirus disease 2019 (COVID-19) have not been fully elucidated. A retrospective study was conducted in patients with COVID-19 to evaluate the influence of LHQW on laboratory results related to the disease, and to provide evidence for the clinical practice of TCM. Materials and methods: We retrospectively collected 248 patients who met the moderate type COVID-19 diagnostic criteria, and received treatment in Tongji Hospital. Patients were divided into control (158 cases, standard treatment) and LHQW treatment (90 cases, standard treatment combined with LHQW) groups according to the different treatments administered. All laboratory data were obtained after 5-7 days' treatment. Results: In this study, the average patient age was 58.95 years and 131 patients were male. The two groups were comparable in demographic characteristics, symptoms, and treatment. Compared with in the control group, Ddimer and erythrocyte sedimentation rate were significantly lower in the LHQW treatment group (2.47 +/- 4.67 vs. 1.68 +/- 3.61; 44.47 +/- 30.24 vs. 35.39 +/- 27.43; both P < 0.05). Lymphocyte counts, albumin and hemoglobin levels were higher in the LHQW treatment group than those in the control group (1.00 +/- 0.46 vs. 1.13 +/- 0.5; 34.39 +/- 5.2 vs. 35.71 +/- 4.76; 127.03 +/- 16.58 vs. 131.11 +/- 14.66; both P < 0.05). Conclusion: The study showed that LHQW significantly improved laboratory results of patients with COVID-19 and could be effectively applied alongside standard treatment of patients with moderate type COVID-19, providing preliminary clinical research evidence for the use of TCM in treatment of this disease.