Impact of notification by NIOSH of a cohort of chemical workers at possible increased risk of occupationally induced bladder cancer was assessed. All hourly employees who had worked at a facility in Atlanta, Georgia, between January 1, 1940 and December 31, 1972, where carcinogenic amines such as beta-naphthylamine (91598) (BNA) had been manufactured or used since the 1940s constituted the initial cohort of 1,385 workers. The cohort list included those still alive as determined from records. A letter that gave a telephone number for information and clinic appointments was sent. A second letter sent to non respondents emphasized that an asymptomatic state was no guarantee that the person was disease free. Non respondents were contacted by telephone to ascertain receipt of letters, whether content was understood, and whether participation was planned. A bladder cancer screening clinic and follow up program were established. Response was evaluated by administering to participants a questionnaire about source of notification and awareness of the risks of BNA. The role of the media was evaluated. Of the final cohort of 1,094, 364 letters were returned as undeliverable, and 515 in town and 181 out of town recipients responded by making appointments for screening, declaring no interest, or indicating private screening. By September, 1982, 77 percent of the total cohort was screened. Over 90 percent of those who received the letter understood it and over 75 percent discussed it with others. Of 379 in town and 137 out of town workers, 64.7 and 38.4 percent, respectively, had previously heard of BNA. The media was a part of the notification process and registered its impact. The authors conclude that a more systematic approach to meet the needs of groups at high risk for occupational disease is needed.