BACKGROUND The shortage of organ donors for kidney transplants has made the expansion of the kidney donor pool a clinically significant issue. Previous studies suggest that kidneys from donors with a history of intravenous (IV) drug, cigarette, and/or alcohol use are considered to be a risky choice. However, these kidneys could potentially be used and expand the kidney supply pool if no evidence shows their association with adverse transplant outcomes. METHODS This study analyzed the United Network for Organ Sharing dataset from 1994 to 1999 using Kaplan-Meier survival analysis and Cox modeling. The effects on transplant outcome (graft and recipient survival) were examined with respect to the donors' IV drug use, cigarette smoking, and alcohol dependency. Covariates including the recipient variables, the donor variables, and the transplant procedure variables were included in the Cox models. RESULTS The results show that the donors' history of cigarette smoking is a statistically significant risk factor for both graft survival (hazard ratio=1.05, P<0.05) and recipient survival (1.06, P<0.05), whereas neither IV drug use nor alcohol dependency had significant adverse impact on graft or recipient survival. CONCLUSIONS Assuming that adequate testing for potential infections is performed, there is no evidence to support avoiding the kidneys from donors with IV drug use or alcohol dependency in transplantation. Utilizing these kidneys would clearly expand the potential pool of donor organs.