Common wisdom believes user diversity improves the performance of an information system-development project by providing a broad wealth of knowledge to the setting. The ability of an organization to capitalize on the diversity requires an understanding of how such diversity impacts the performance of the project and whether common processes are still relevant in the presence of diversity. Learning by an organization is an established link to success and may serve as a mediator between user diversity and project performance. Still, the environmental condition of user diversity must fit in with established procedures. In this study, management review is used as a base process to examine whether user diversity is significant to the success of a system either directly or with learning as a mediator. A survey is administered in the US and Taiwan that is used to test a model of the relationship between user diversity and project performance, specifically when organizational technology learning is a mediating variable and management review processes are considered as control processes. The findings confirm the expected results for management review and learning, but show user diversity to be fully mediated by organizational technology learning. The results imply that user diversity should be considered an environmental factor to promote learning, but may not be important in the completion of any particular project.