Dropout from substance use disorder treatment is usually investigated and understood from a perspective of quantitative patient-related factors. Patients' own perspectives (user perspective) are rarely reported. This study, therefore, aimed to explore patients' own understanding of their dropout from residential substance use disorder treatment. The participants were 15 males and females, aged 19-29 years, who had dropped out of residential substance use disorder treatment at the Department of Addiction Treatment, Oslo University Hospital, Norway. Qualitative methodology with semistructured interviews was used to explore how the participants described their dropout and their reasons for doing so. Thematic analysis was used as the framework for analyzing the data derived from the interviews. Dropout had different meanings for different participants. It was understood as a break from treatment, as an end to treatment, or as a means of reduced treatment intensity. Against that background, four main themes for dropout were found: drug craving, negative emotions, personal contact, and activity. Patient and treatment factors seem to interact when participants explore reasons for their dropout. A complex pattern of variables is involved. As remedies, participants suggested that substance use disorder treatment should provide more focus on drug craving and training to understand and tolerate emotional discomfort. They also wanted closer contact with the staff during treatment, more activities, and rigorous posttreatment follow-up. These findings from the user perspective have important implications for substance use disorder treatment, clinical and social work practice, management, and research.