When evaluating a living kidney donor and recipient with a father-child relationship, it may be discovered that the two are not biologically related. We analyzed data from the United Network for Organ Sharing and the Canadian Organ Replacement Registry to determine how frequently this occurs. We surveyed 102 potential donors, recipients, and transplant professionals for their opinion on whether such information should be disclosed to the donor-recipient pair. We communicated with transplant professionals from 13 Canadian centers on current practices for handling this information. In the United States and Canada, the prevalence of father-child living kidney donor-recipient pairs with less than a one-haplotype human leukocyte antigen match (i.e., misattributed paternity) is between 1% and 3%, or approximately 0.25% to 0.5% of all living kidney donations. Opinions about revealing this information were variable: 23% strongly favored disclosure; whereas, 24% were strongly opposed to it. Current practices are variable; some centers disclose this information, whereas others do not. Discovering misattributed paternity in living donation is uncommon but can occur. Opinions on how to deal with this sensitive information are variable. Discussion among transplant professionals will facilitate best practices and policies. Strategies adopted by some centers can be considered.