In organ donation, the donor, recipient, and transplant team must all accept potential health risks to the donor and any uncertainties. To gauge these risks, we surveyed general altruism and risk-taking behaviors in 112 potential donors, 111 potential recipients, and 51 transplant professionals. Next, participants indicated their risk thresholds for long-term donor hypertension, cardiovascular disease, and kidney failure that would stop them from pursuing living donation and their willingness to proceed when risks were uncertain. The three groups had similar general altruism and risk-taking behaviors. Potential donors were significantly more willing to accept greater long-term donor risks than potential recipients and transplant professionals. Moreover, these potential donors were significantly more likely to agree that living donation was acceptable when long-term donor risks were uncertain. Potential kidney donors readily accept high long-term risks, whereas potential recipients were the most averse to donor risk. Our study shows that transplant professionals facilitate the best decisions by appreciating the willingness of their patients to accept donor health risks along with their own risk tolerance.