Background: Thyroid Carcinoma (TC) is the most common endocrine carcinoma accounts for 90% of all endocrine malignancies, awareness of health belief can help patients with TC to prevent most of complication. Aim of this study: Was to assess health belief model among patients' with thyroid carcinoma. Research design: A descriptive research design was utilized in this study. Setting:The study was conducted at Damanhour Oncology Center in El-Beheira Governorate. Sample: A convenient sample included 120 patients. Tools: Two tools were used in this study. Tool I): An interview questionnaire to assess; A) Socio-demographic characteristics. B) Patients' knowledge regarding thyroid carcinoma. C) Reported practices regarding thyroid carcinoma. Tool II): Health belief scale of studied patients regarding thyroid carcinoma. Results: 38.3% of studied patients aged from 40 to less than 50 years old with mean ± SD 43.00±8.98, while 55% of them were female and 35.8% of them had secondary education. In addition, 47.5% of studied patients had total poor knowledge regarding thyroid carcinoma. As regard patients' practices, 54.2% of studied patients had satisfactory total practices regarding thyroid carcinoma. 45.8% of them had unsatisfactory total practices, while 19.2% of studied patients had high total health belief, and 35% of them had low total health belief regarding thyroid carcinoma. Conclusion: There were highly statistically significant relation between studied patients' total practices level and their total health belief regarding thyroid carcinoma. Recommendations: Health educational program should be developed and implemented for patients with thyroid carcinoma to enhance their health belief.