Background and aims: Euthanasia is a controversial issue related to the right to die. Although euthanasia is mostly requested by terminally sick individuals, even in societies where it is legal, it is unclear what medical conditions lead to euthanasia requests. In this scoping review, we aimed to compile medical conditions for which euthanasia has been requested or performed around the world. Methods: The review was preferred reporting items for systematic reviews and meta-analysis for scoping reviews (PRISMA-ScR) checklist. Retrieved search results were screened and unrelated documents were excluded. Data on reasons for conducting or requesting euthanasia along with the study type, setting, and publication year were extracted from documents. Human development index and euthanasia legality were also extracted. Major medical fields were used to categorize reported reasons. Group discussions were conducted if needed for this categorization. An electronic search was undertaken in MEDLINE through PubMed for published documents covering the years January 2000 to September 2022. Results: Out of 3323 records, a total of 197 papers were included. The most common medical conditions in euthanasia requests are cancer in a terminal phase (45.4%), Alzheimer's disease and dementia (19.8%), constant unbearable physical or mental suffering (19.8%), treatment-resistant mood disorders (12.2%), and advanced cardiovascular disorders (12.2%). Conclusion: Reasons for euthanasia are mostly linked to chronic or terminal physical conditions. Psychiatric disorders also lead to a substantial proportion of euthanasia requests. This review can help to identify the features shared by conditions that lead to performing or requesting euthanasia.