Free and informed consent is generally acknowledged as the legal andethical basis for living organ donation, but assessments of livingdonors are not always an easy matter. Sometimes it is necessary toinvolve psychosomatics or ethics consultation to evaluate a prospectivedonor to make certain that the requirements for a voluntary andautonomous decision are met. The paper focuses on the conceptualquestions underlying this evaluation process. In order to illustrate howdifferent views of autonomy influence the decision if a donor's offer isethically acceptable, three cases are presented – from Germany, theUnited States, and India. Each case features a person with questionabledecision-making capacity who offered to donate a kidney for a siblingwith severe renal insufficiency. Although the normative framework issimilar in the three countries, different or sometimes even contraryarguments for and against accepting the offer were brought forward. Thesubsequent analysis offers two explanations for the differences inargumentation and outcome in spite of the shared reference to autonomyas the guiding principle: (1) Decisions on the acceptability of a livingdonor cannot simply be deducted from the principle of autonomy but needto integrate contextual information; (2) understandings of the wayautonomy should be contextualized have an important influence on theevaluation of individual cases. Conclusion: Analyzing the conceptualassumptions about autonomy and its relationship to contextual factorscan help in working towards more transparent and better justifieddecisions in the assessment of living organ donors.