Computed tomography (CT) has been established as the method of choice for imaging kidney stones with high sensitivity and accuracy. Further, dual-energy CT (DECT) showed the capability of differentiating uric-acid (UA) from non-UA stones with 90-100% accuracy. DECT depends on acquiring two images at different energy levels, from which a material-specific color-coded image is generated. With the invention of dual-source (DS) scanners, both low- and high-energy images are acquired simultaneously. However, DECT can also be performed by sequential acquisition of both images on single-source (SS) scanners. Although motion artifacts generally result in distorted anatomy and blurring, in stone imaging they may lead to stone misclassification. In this study, we investigate the effects of motion artifacts on stone classification using both SS and DS DECT. The results show that stone misclassification may be significantly higher in SS DECT, especially when multiple stones with different types lie in close proximity.