Describe some clinical and subclinical characteristics in Hashimoto's chronic thyroiditis patients at Thai Nguyen National Hospital. Subjects and methods: Cross-sectional description of 41 patients with Hashimoto's chronic thyroiditis at Thai Nguyen National Hospital, diagnosed based on the diagnostic criteria of Takashi Akamizu from January 2019 to August 2021. Results: Female/male ratio = 12.67/1. The mean age of the patients was 42.32 ± 18.15 with 48.8% of the patients from 40 to 60 years old. 85.4% of patients showed signs of fatigue; 51.2% with dry, dull skin; 41.5% with goiter, 29.3% with sluggishness, fear of cold. The average anti-TPO concentration was 699.40 ± 438.83 UI/ml, anti-TPO (+) was 95.1%. Most patients with thyroid function are clinically hypothyroidism, account for 73.2%; 9.7 patients with subclinical hypothyroidism and 17.1% with euthyroid. Conclusion: Hashimoto's chronic thyroiditis is an autoimmune disease commonly seen in middle-aged female patients. The most common clinical symptoms are fatigue, dry skin, and darkening of the skin. Most patients with anti-TPO (+) and thyroid function are clinically hypothyroidism.