Sustainable purchasing policies and e-procurement are both fast becoming popular topics across city governments in the United States. As these two relatively new initiatives meet, the relationship they share has some promising implications that have gone mostly unexplored until now. E-procurement systems have gained a reputation of being one of the most effective ways to advance sustainable purchasing goals, but the belief alone may not be enough to create director-level buy-in throughout city governments. The possible link between these two tools was identified while working with the City of Phoenix’s Office of Environmental Programs. While helping them integrate sustainability considerations into their procurement process, it was noticed that e-procurement systems typically facilitated many of the obstructions the department faced and that there could be a positive relationship between their already existing e-procurement system and their sustainable purchasing policy. To investigate this relationship deeper, a survey of city government procurement was sent to 1,845 directors from Finance, Public Works, and Environmental departments across 791 U.S. cities. These decision-makers answered questions relating to their assessment of how sustainable purchasing policies are implemented and the extent to which their city uses an e-procurement system. Tests of independence were then performed to determine if a relationship between different e-procurement activities and perceived success of cities’ sustainable purchasing policies existed. Results show that the use of an environmentally friendly database of products and services in a city’s e-procurement system is the single most important e-procurement pursuit cities can undertake to influence the opinions that city managers have regarding the success of their sustainable purchasing policy. By understanding this connection, The City of Phoenix and other cities facing the same challenges are able to develop best practices to leverage e-procurement for purchasing sustainably and fully implementing their sustainable purchasing policies.