Background & Aim: Thyroid nodules represent one of the most prevalent endocrinological findings in clinical practice, with sonographic prevalence ranging from 19–67%. The principal diagnostic challenge lies in non-invasively differentiating malignant from the far more prevalent benign thyroid nodules. This study aimed to systematically evaluate the gray scale, color Doppler flow imaging (CDFI), and spectral Doppler characteristics of thyroid nodules and to correlate these sonographic features with fine needle aspiration cytology (FNAC) findings. Methods: This prospective, descriptive cross-sectional study was conducted at the Department of Radiodiagnosis, IGGMC, Nagpur, over a 24-month period (November 2017 – November 2019). Eighty consecutive patients presenting with thyroid swelling underwent high-resolution grayscale ultrasonography and color/spectral Doppler evaluation using a Philips HD11XE machine with a 7–12 MHz linear transducer. Nodule characteristics assessed included size, shape, echotexture, margins, halo, internal calcification, cervical lymphadenopathy, and vascularity (CDFI). Spectral Doppler parameters including peak systolic velocity (PSV), pulsatility index (PI), and resistive index (RI) were recorded. Nodules were stratified using the Thyroid Imaging Reporting and Data System (TI-RADS). All cases subsequently underwent USG-guided FNAC, and histopathological biopsy where applicable. Statistical analysis was performed using chi-square test and receiver operating characteristic (ROC) curve analysis; p < 0.05 was considered statistically significant. Results: Of 80 patients (78.75% female; mean age 38.4 years), 71 (88.75%) harbored benign and 9 (11.25%) malignant nodules. Malignant lesions were significantly more frequent in patients aged >40 years (p < 0.001). On gray scale, irregular margins (88.89% vs 0%), hypoechogenicity (77.78% vs 8.45%), and the presence of microcalcifications (77.78% vs 42.25%) were strongly associated with malignancy (all p < 0.05). On CDFI, intra-nodular vascularity was present in 100% of malignant versus 19.71% of benign lesions (p < 0.001). Spectral Doppler demonstrated RI > 0.75 in 88.89% of malignant nodules (sensitivity 88.89%, specificity 98.59%; p < 0.001) and PSV ≤ 20.4 cm/s in 100% of malignant lesions (p < 0.001). Combined gray scale + Doppler sonography achieved an overall sensitivity of 98% and specificity of 97% for detection of thyroid malignancy. Complete concordance was achieved between USG and FNAC diagnoses for all malignant lesions. Among malignant lesions, papillary thyroid carcinoma and follicular thyroid carcinoma were the most common histotypes, each accounting for 33.33% (3/9 cases), followed by anaplastic carcinoma (22.22%) and medullary carcinoma (11.11%). Conclusion: High-resolution gray scale ultrasonography combined with CDFI and pulse Doppler constitutes a highly sensitive, non-invasive first-line imaging modality for characterizing thyroid nodules. The combination achieves near-complete correlation with FNAC for malignant lesions, potentially reducing the need for unnecessary cytological sampling in clinically benign lesions.