Attitudes are one of the three most-frequently studied independent variables to explain user behavior. However, although psychological literature distinguishes between explicit and implicit attitudes, most of the investigations in the research stream of IS acceptance and usage have a pure focus on explicit attitudes and do not consider implicit attitudes. Explicit and implicit attitudes can be contradictory and both might predict behavioral intention. Therefore, the present research-in-progress focuses on closing the research gap of refraining to differentiate attitudes in explicit and implicit attitudes and hence examining the influence of implicit attitudes on user behavior. Based on the Implicit Association Test (IAT) and surveys, we propose an experimental setting that measures explicit and implicit attitudes to validate the research model. The proposed research might contribute to the research stream of IS acceptance and usage by better predicting behavioral intentions by also considering implicit attitudes. Future results might explain distorted predictions of behavior and reduce the intention-behavior gap. Furthermore, the present research-in-progress introduces a suitable method to measure implicit attitudes.