Scientific, epidemiological, and toxicological data concerning reproductive and developmental health risks have been determined for some chemicals, but data on many chemicals, physical agents, and biological agents are limited and, in some instances, nonexistent. Consequently, there may be considerable uncertainty about what action should be taken to adequately manage potential workplace reproductive health hazards. This guidance statement describes measures to assess the magnitude of potential reproductive and developmental risks in the workplace and presents options to manage the uncertainty associated with these risks.