Background: Thyroid cancer is cancer of thyroid gland; it is most common endocrine cancer worldwide. Statistical data consistently indicates a rise in thyroid cancer over the past three decades, though the reasons for this increase remain controversial. The prevalence of thyroid cancer varies across different geographical regions, influenced by distinct factors. Thyroid enlargement and thyroid cancer are widespread occurrences in TGSH, yet there was a lack of comprehensive data on the extent of thyroid cancer and its associated factors in the study area. Objectives: To assess magnitude and associated factors of thyroid cancer among thyroid enlarged patients in Tibebe Ghion Specialized Hospital, Northwest Ethiopia, 2022-2023. Methods: A cross-sectional study was conducted on patients of 176samples that were visited at TGSH who got thyroid histopathological investigations and surgical care from August- 2022 to August-2023, 160 (91%) patient’s medical records had complete data whereas 16 charts were omitted due to incomplete data. Collected data were recorded review in sheet. SPSS version 25.0 for analysis. Univariate and multivariate binary regression studies were used for detecting the associations between variables. P Value < 0.05 was used to determine the association of variables and or with 95% CI was used to determine the strength. Result: In this study the magnitude of thyroid cancer among thyroid enlarged patients was found to be 14.4% and Papillary thyroid cancer was the predominant type among thyroid cancer sub types, constituting 65.2%. Conclusion: The magnitude of thyroid cancer was higher than that in previous studies in the region; the leading type is papillary thyroid carcinoma, followed by follicular and hurtle-cell thyroid carcinoma. This study found that age greater than 60 years and male sex were significantly associated with thyroid cancer; Key words: Thyroid cancer, Magnitude, Enlarged thyroid.