Background Dementia is a key health issue worldwide. In Sweden, as in other European countries, most persons with dementia live in domestic settings and are often cared for by their family members. This scoping review aims to describe the perspectives of children and young adults with a parent diagnosed with dementia. Young family members may be alone and without support despite their high level of care burden. Design and methods Three electronic databases (PubMed, Web of Science and PsycINFO) were used to search for English-language articles focusing on children and young adults between the ages of 6 and 34 who have a parent diagnosed with dementia. A thematic synthesis of the included articles was performed. Findings Sixteen original published qualitative studies were identified. These studies were categorised based on information about the authors, year of publication, study location, participants, aim of the study, data collection, analysis and main findings. Five main analytical themes were identified: (1) children and young adults identify changes in their parents’ behaviour and personality, (2) children and young adults experience changed roles and relationships within the family, (3) children and young adults need to cope with an uncertain future, (4) children and young adults relate changes in their parent to their own mixed emotions and (5) children and young adults need help and seek it out but experience inadequate support. Conclusions The children and young adults in the included studies seem to provide significant levels of care and support to their affected parent, which may affect their own health, social relations, community participation, employment, education, finances and sense of security. This means that it is important for health care systems and social services to identify barriers to these young family members’ access to relevant care and support for themselves.