Social robots are increasingly used in different services such as education, hospitality, healthcare, and elderly care. These robots are often adopted to provide people with information and guidance, which sometimes can be quite different from people’s expectations. Therefore, it is important to understand whether similar or dissimilar opinions or attitudes of a focal subject held by the user and robot affects the user’s perception of the robot and future adoption intentions. We propose that robot design (positive facial expressions and verbal sentiments) may moderate the effect of attitude dissimilarity on robot perception. It is well-documented in the psychology literature that attitude similarity affects human-human relationships; however, no such study has been undertaken in human-robot interactions. Our results showed that when the robot expressed its views using a neutral facial expression and verbal sentiment, attitude similarity influenced robot perception, i.e., those participants who had similar (vs. dissimilar) attitudes as the robot perceived the robot to be positive (vs. negative). However, when the robot expressed its opinion with a positive facial expression and verbal sentiment, participants judged the robot as positive regardless of attitude similarity between the user and the robot. These results indicate that positive facial expressions and the verbal sentiment of a robot can nullify any negative effect when a user and a robot share very different opinions.