Objective: The additive of conventional magnetic resonance imaging ( MRI ) is evaluating the deep placed nodules and presence of distant metastases where USG might remain insufficient. DWI is noninvasive modality without using ionizing radiation and may differentiate benign and malignant nodules. Material and Methods:We prospectively evaluated 47 patients who demonstrated solitary thyroid nodules on ultrasonographic examination and underwent DWI of the thyroid gland. Apparent diffusion coefficient (ADC) values of these nodules were calculated and compared to histopathology results obtained with surgery. Whether a distinction for malignanvy nodules could be achieved by using mean ADC values were evaluated by statistical analysis. Results: The mean ADC values of malignant thyroid nodules were lower than benign nodules and the difference was statistically significant. (p < 0.01). There were also statistically significant differences between the ADC values of benign thyroid nodules of different types (p < 0.05). When a mean ADC cut off value of 1.81 x 10¯³ mm² / sn was used in predicting malignancy, a 85.7 % sensitivity, 69.7 % specificity and 74.47 % accuracy were obtained. Conclusion: Since the mean ADC values of malignant thyroid nodules differs lower than benign nodules, DWI may be used to differentiate benign to malignant nodules.