An estimated 10% of children and adolescents with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) experience eating difficulties; however, little is known about why these difficulties develop, what the impact is or how to manage them. Semi-structured interviews were conducted with adolescents (aged 12-17 years) attending a specialist service who have a primary diagnosis of CFS/ME and experience nausea, abdominal pain and/or eating difficulties. A total of 11 adolescents were interviewed (eight female, mean age: 15 years). Transcripts were analysed thematically using techniques of constant comparison which commenced soon after data collection and informed further interview protocols. Adolescents perceived their eating difficulties were caused by abdominal symptoms, being too fatigued to eat and changes to their senses of taste and smell. Some of the adolescents recognised how their eating difficulties were exacerbated and maintained by psychological factors of low mood and anxiety. The adolescents eating difficulties had a negative impact on their weight, fatigue, socialising and family life. They perceived helpful interventions to include modifying their diets, families adjusting and also medical interventions (e.g. medication). Adolescents identified that early education and support about diet and eating habits would have been helpful. If adolescents diagnosed with CFS/ME develop eating difficulties, this has a significant impact on their quality of life, illness and on their families. Not eating increases fatigue, low mood and anxiety which further exacerbates the eating difficulties. Clinicians should screen for eating difficulties in those with symptoms of nausea and abdominal pain, warn adolescents and their families of the risk of developing eating difficulties and provide interventions and support as early as possible.