We conducted a retrospective study on 43 patients diagnosed with dengue hemorrhagic fever (DHF) according to the standards of the Ministry of Health in 2019. Our objective is describing the epidemiological, clinical, and subclinical characteristics of patients with (DHF) in Thai Nguyen, we got results: patients with age 35 - ≤ 60 was accounted for 58.1%, age ≤ 16 was 4.6%. Patients live in 15/21 wards; 01/11 communes in Thai Nguyen city; 4/6 districts include Phu Binh, Vo Nhai, Dai Tu; Dong Hy. The proportion of patients with symptoms of fever was 100%, bleeding was 31/43 (72.1%), abdominal pain in the liver or tenderness was 10/43 (23.2%), vomiting was 7/43 (16.3%), diarrhea (9.3%), pleural effusion and acites (4.6%). Patients with a hematocrit of 35-45% were 21/43 (48.8%); hematocrit > 45% accounted for 20/43 (46.6%). Patients with platelet 5- < 50 accounted for 22/43 (51.2%); 20/43 (46.5%) patients had platelets reduced from 50 - < 150 G/l; No patient had platelets < 5 G/l. Patients with AST and ALT of 40 - < 400 (U/l) accounted for the highest proportion of 35/43 (81.4%) and 30/43 (69.8%), respectively. 2/43 (4,6%) patients with AST ≥ 1000 (U/l); 1/43 (2.3%) patients had ALT ≥ 1000 (U/l). 100% patients in the study were cured and discharged from the hospital, mainly patients with DHF and DHF with warning signs.