Aim:To assess some quantitative spectral Doppler parameters, resistivity index (RI) and acceleration time (AT) together to show their reliability for differential diagnosis of parenchymal thyroid diseases. Methods: This study was conducted in the Department of Radiology, Maharishi Markandeshwar University, Solanfor the period of 1 year. Patientsweredivided into five groups such as group I (normal); group II had first detected, early untreated Hashimoto disease(EH);groupIII comprised of chronic Hashimoto patients that are under treatment and/or follow up (H); group IV had multinodular parenchymal hyperplasia (M) and group V had nodular hyperplasia with Hashimoto (HM). They underwent spectral Dopplerultrasound usingPhilipsAfiniti 70 G machine by a linear 5-12 MHz probe. Quantitative spectral Doppler parameters such as resistivity index (RI) and acceleration time (AT) were recorded.