There is empirical evidence to suggest that problematic smartphone use (PSU) is associated with mental health problems including anxiety in educational settings. This qualitative study explored attitudes towards—and self-reported impacts of—smartphone use among British young adult students, as well as perceived causes of PSU. Free-response written accounts were gathered from 265 British undergraduates at an English university. Open-ended questions were asked about their attitudes towards smartphone use, their reasons for using their smartphones, and what they perceived as the consequences of their smartphone use. Narratives were analyzed using framework analysis and a thematic framework was identified. The three main consequences of PSU described by participants were (1) uncontrolled frequent checking of smartphones, (2) using smartphones late at night, and irrelevant use of smartphones in class. The main reported explanations for PSU were fear of missing messages, boredom in class, poor self-regulation, and external reasons (e.g., boring lectures). Smartphone use was reported to have both positive and negative impacts on young adults’ life satisfaction, social relationships, physical health, and study. Many participants reported that they need to develop better self-regulation to address their PSU. Findings suggest that smartphone use can have benefits as well as potentially causing harm among university students. PSU can—in some cases—be understood as reflecting mental well-being issues, poor self-regulation, and social problems.