Introduction and objective:
The thyroid gland is responsible for the production of key hormones, and Hashimoto’s disease is a common cause of hypothyroidism. Effective treatment requires a proper diet and consideration of interactions between medications and nutrients. The aim of this study was to assess patients’ knowledge of nutrition in the course of Hashimoto’s disease.

Material and methods:
The study was conducted in 2023, using a proprietary, anonymous survey questionnaire distributed online via social media. The study involved 220 participants, including 176 women and 44 men, aged between 19–54. Respondents’ answers were scored, with a maximum possible score of 40. The collected data were statistically analyzed using Microsoft Excel and Statistica software.

Results:
A statistically significant correlation (p=0.027) was found between the duration of the disease and the level of respondents’ knowledge. People who had been ill for a shorter period of time had a lower level of knowledge. Men more frequently than women presented a very low level of knowledge. A low level of knowledge was also more common among urban inhabitants who, at the same time, more often obtained high or very high scores. People who had been ill for less than a year showed a level of knowledge that was twice as low, compared to patients with a longer history of the disease. The lowest level of knowledge was observed in the age groups 18–25 and over 46

Conclusions:
Patients' knowledge of comprehensive diet therapy for Hashimoto’s disease is insufficient. Therefore, it is necessary to intensify educational activities aimed at raising patient awareness in this area