This study aimed to investigate the relationships among undergraduates' problematic information security behavior (PISB), compulsive internet use (CIU), mindful awareness, and demographic factors in Taiwan. The convenience sampling was performed at three universities in southern Taiwan, and 514 undergraduates were selected as participants. A cross-sectional survey research design was used, and a hierarchical regression analysis was performed. Current results indicated that undergraduates with non-science majors had a higher level of PISB than undergraduates with science majors. Mindful awareness was negatively associated with undergraduates' PISB, whereas CIU was positively associated with undergraduates' PISB. Furthermore, the association between mindful awareness and PISB was moderated by the level of CIU, such that the relationship between mindful awareness and PISB was stronger in undergraduates with low CIU than in undergraduates with high CIU. In other words, a one standard deviation unit increase in mindful awareness predicted a greater reduction in PISB in undergraduates with low CIU relative to undergraduates with high CIU. The main implication of these findings is that although increasing mindfulness awareness may be related to reducing PISB in students in general, it appears that mindfulness awareness training may be more effective in improving PISB in students with low CIU relative to those with high CIU. Hence, if CIU is particularly problematic in certain students, then it may be helpful to specifically target CIU first with treatment (e.g., cognitive-behavioral therapy) not only to alleviate problems associated with CIU but also to allow mindfulness awareness training to better improve PISB.