Problematic smartphone use and nomophobia have been associated with several psychopathological conditions. However, little is known about the interconnectedness of these phenomena and conditions that influence them, despite previous studies discussing the mediating effects of variables such as boredom proneness, self-control, and attachment anxiety. We differentiate them as separate phenomena and investigate the role of emotional wellbeing and mindfulness in influencing them through a quantitative study with a sample of 282 participants. Statistical analysis shows that negative affective states indirectly influence problematic smartphone use through nomophobia while gender and occupation have an impact of nomophobia as well. Further, mindfulness has no bearing on problematic smartphone use or nomophobia. The study demonstrates subtle differences between two dark side phenomena and signifies the varying effects on them. It furthers the argument that dark side phenomena are interrelated and highlights the need to explore mitigation mechanisms beyond mindfulness to deal with these phenomena.