Use of the PharmaCloud can improve the quality of healthcare, but improvements are likely to be thwarted if physicians resist using the system. This study uses the dual-factor model to explain physicians' resistance behaviors to system usage. The results of a field survey conducted in Taiwan showed that physicians' resistance to using the PharmaCloud stemmed from regret avoidance, inertia, perceived value, and perceived threat. These results also indicate that system, information, and service qualities are the key determinants of the behavioral intention to use. This research advances the theoretical understanding of user acceptance and resistance to technology post-implementation and offers practical implications.