Thyroid cancer is one of the most significant diseases in modern endocrinology and oncology, and its early and accurate diagnosis plays a crucial role in treatment outcomes and prognosis. This article compares the results of ultrasound examination and cytological analysis in diagnosing thyroid cancer. The aim is to evaluate and compare the accuracy, effectiveness, and clinical applicability of the two diagnostic methods. The study analyzed patients’ clinical data, characteristics of thyroid nodules, and diagnostic results. Ultrasound was used to assess the size, shape, growth patterns, and vascularization of the nodules. Cytological examination, on the other hand, allowed for determining whether the nodule was benign or malignant based on cytological samples. The results showed that although ultrasound has high sensitivity, cytological examination provides higher accuracy in detecting malignant nodules.