To evaluate the role of ultrasound as the primary diagnostic imaging modality in thyroid disease. Methodology: Patients suspected to have thyroid disease were included in the study. Ultrasound was done as initial diagnostic imaging method for thyroid lesions and evaluated accordingly. These thyroid lesions were subjected to ultrasound guided FNAC, for confirmation of diagnosis. Later the validity of ultrasound diagnosis in relation to FNAC diagnosis was studied. Results: Ultrasonography showed relatively high sensitivity and specificity for diagnosing and characterizing thyroid disease. For thyroid adenomas, colloid cyst and multinodular goiter, the sensitivity of ultrasound was 98.55% and specificity in our study was 100%/. USG could considerably differentiate malignant and non-malignant thyroid lesions. USG showed relatively high diagnostic rate. USG guided FNAC was a safe procedure and yielded high diagnostic yield for detection of thyroid diseases. Conclusion:Above data suggests that USG can be used as a primary imaging modality with high sensitivity and specificity for overall diagnosis and characterization of thyroid diseases. USG helps in guiding FNAC for confirmation of diagnosis.