The development, performance, effectiveness, and impact of risk communication to workers were considered. The methodological issues were divided into three areas: the content of notification; the process of notification; and the evaluation of the notification. The content must be such that the complexity of the information is imparted to the recipient, but in a language or manner which does not upset or unduly alarm the worker. The process used to communicate to the worker includes the development of materials, the choices of communication channels, the implementation of the notification, the provision of medical, social, psychological, financial, and legal support, and the involvement of the recipients of risk communication in the process. Few formal evaluations have been conducted of individual worker notification projects. In evaluating effectiveness, the authors used a toll free number to allow for immediate questions and feedback from those notified. A recently mailed notification of 1663 workers at risk of bladder cancer from chemical exposures generated 40 calls dealing primarily with requests for general information or for information on screening.