Although paired donation, list donation and non-directed donation allow more recipients to receive living donor transplants, policy makers do not know how willing incompatible potential donors are to participate. We surveyed 174 potential donors ruled out for ABO-incompatibility or positive cross-match about their participation willingness. They were more willing to participate in paired donation as compared to list donation where the recipient receives the next deceased donor kidney (63.8% vs. 37.9%, p < 0.001) or non-directed donation (63.8% vs. 12.1%, p < 0.001). Their list donation willingness was greater when their intended recipients moved to the top versus the top 20% of the waiting list (37.9% vs. 19.0%, p < 0.001). Multivariate logistic regression modeling revealed that potential donors' empathy, education level, relationship with their intended recipient and the length of time their intended recipient was on dialysis also affected willingness. For paired donation, close family members of their intended recipient (odds ratio (OR) = 3.01, confidence intervals (CI) = 1.29, 7.02), with high levels of empathy (OR = 2.68, CI = 1.16, 6.21) and less than a college education (OR = 2.67, CI = 1.08, 6.61) were more willing to participate compared to other donors. Extrapolating these levels of willingness nationally, a 1-11% increase in living donation rates yearly (84-711 more transplants) may be possible if donor-exchange programs were available nationwide.