In recent years there has been a rapid increase in the use of wireless communications devices and a great deal of research has been carried out to investigate possible biological or human health effects resulting from their use. The U.S. Food and Drug Administration asked the National Research Council to organize a workshop to identify research needs and gaps in knowledge in the areas of dosimetry and exposure, epidemiology, human laboratory studies, mechanisms, and animal and cell biology. The workshop did not include the evaluation of health effects or the generation of recommendations relating to how identified research needs should be met. Some needs and gaps identified at the workshop include: (1) characterization of exposures from wireless devices and RF base station antennas in juveniles, children, fetuses, and pregnant women and (2) evaluation of devices that use newer technologies (e.g., texting, web-surfing).