Accessible SummaryWhat is known on the subject? Problematic internet use (PIU) negatively affects adolescents' lives biopsychosocially. There is limited qualitative research examining the problem of PIU in adolescents. These studies focused more on the non‐clinical population. Adolescents' perceptions of the internet, their thoughts, feelings and behaviours in situations where they can and cannot access the internet have rarely been examined. What does the paper add to existing knowledge? This research provides an in‐depth look at the experiences of adolescents with PIU in a clinical population. Unlike previous studies, adolescents mentioned that they turned to the internet for reasons such as lack of activity, their need to spend time with their friends and better getting along with people they met on the internet. They also described a world without internet as apocalypse, desert and grave. In this study, a holistic emphasis was placed on the thoughts, feelings and behaviours of adolescents in situations where they could and could not access the internet. This may contribute especially to mental health nurses working in clinics in terms of understanding the thought‐emotion and behaviour patterns of adolescents with PIU. Adolescents also stated that their lives were affected positively and negatively as a result of PIU. What are the implications for practice? Mental health nurses can use activity therapy, behaviour modification: social skills, coping enhancement, parent education: adolescent, self‐awareness enhancement, cognitive restructuring, emotion and behaviour management interventions to reduce the risk of PIU and the problems it causes for adolescents. What are the implications for practice? Mental health nurses can use activity therapy, behaviour modification: social skills, coping enhancement, parent education: adolescent, self‐awareness enhancement, cognitive restructuring, emotion and behaviour management interventions to reduce the risk of PIU and the problems it causes for adolescents. AbstractIntroductionStudies on problematic internet use (PIU) are mostly on the non‐clinical population. Understanding the experiences of adolescents with PIU is critical in shaping nursing interventions and improving the quality of care.AimsA comprehensive description of the experiences of adolescents with PIU.MethodsIn the study, descriptive phenomenology design, one of the qualitative research methods, was used. Data were collected using a personal information form and a semi‐structured interview form and analysed using Giorgi's phenomenological method (n = 11).ResultsAs a result of the content analysis, five main themes were identified: reasons of PIU, internet‐related perceptions, experiences in accessing the internet, experiences in not being able to access the internet and consequences of internet use.DiscussionDifferent from previous studies, adolescents stated that they use the internet because of their lack of activity and their need to spend time with their friends. They stated that when they could not access the internet, they thought they could never live without the internet and started quarrel.