Objective: This article provides the background for consideration of exposure registries to address potential disease risks in nanomaterial workers.

Methods: The history of exposure registries is reviewed with a focus on their purpose and criteria for establishment.

Results: A rationale is presented for developing registries of nanomaterial workers, and unresolved obstacles and challenges are identified. These include issues on inclusion criteria, funding, potential for legal risks, access to data, confidentiality of business information, privacy, and workers' expectations.

Conclusion: If society is to gain the benefits from nanotechnology, it must take precautions and demonstrate care for those, such as workers, who may be most at risk of adverse effects. Establishing exposure registries is a part of such a precautionary and caring approach.