Introduction Thyroid diseases are major health problems that are manifested by alteration in hormone secretion, enlargement of the thyroid gland (goitre), or both. Identifying and characterizing lesions of the thyroid gland has a pivotal role since most of the lesions require medical or surgical management. Fine needle aspiration cytology (FNAC) is an important initial screening tool and histopathologic examination is the gold standard in the definitive diagnosis of thyroid disease. Objectives To assess histopathologic patterns and cytohistologic correlation of thyroid lesions among patients with thyroid biopsy. Methods A five-year retrospective study was conducted with a review of 581 biopsies submitted from thyroidectomy specimens at Jimma University Medical Centre (JUMC), Pathology Department from September 2015 to September 2020. This also includes a review of 286 cases in which fine needle aspiration was done prior to surgery. Data was analysed using Statistical Package for the Social Sciences (SPSS) version 26. Descriptive and analytic studies were done. Cross tabulation, chi square (χ2 ) test and logistic regression with multivariate analysis were done to look for associations between the study variables. Results Majority of thyroid lesions were found to be non-neoplastic and 149 (25.6%) were neoplastic. Colloid goitre was found in 417 (71.8%) cases. Adenoma, carcinoma, and thyroiditis accounted for 54 (9.3%), 95 (16.3%) and 12 (2.1%) cases respectively. Among 286 FNAC results, cyto-histologic correlation was achieved in 233 (86.6%) cases. Sensitivity and specificity of FNAC were 71% and 92.7% respectively, with diagnostic accuracy of 86.6%. Conclusion Nodular colloid goitre is by far the most common thyroid lesion and papillary thyroid carcinoma (PTC) is the most frequent histologic type of malignancy. FNAC remains a sensitive, specific and accurate tool in the evaluation and management of thyroid lesions.