This study examines the differential effects of hedonic vs. utilitarian robots, using a between-subjects experimental design, whereby 48 college students in Korea were randomly assigned to interact with either a Pleo (Dinosaur robot) or a Roomba (vacuum-cleaning robot). Results revealed that hedonic robot (HR) users perceived more enjoyment than utilitarian robot (UR) users, whereas UR users perceived more usefulness and ease-of-use than HR users. Users with high tendency for parasocial interaction (PSI) and high anthropomorphism had more positive attitudes towards robots than their counterparts with low levels of these traits. HR users with high anthropomorphism and PSI had the most positive attitudes than all other combinations of variables. These results indicate that individual differences play a significant moderating role on user attitudes toward hedonic and utilitarian robots. The results of this study suggest that robot developers and marketers should take seriously the labeling of robots as hedonic or utilitarian, and also consider users' individual differences in order to maximize benefits of human-robot interactions.