During a 5-month period, community residents were eligible to win monthly prizes and a grand prize by buckling up all automobile occupants when driving. Any car containing at least one child judged to be under the age of 13 that was spotted by a member of the local Child Passenger Safety Council, and in which all occupants were buckled up, was entered in a monthly lottery. Systematic monitoring of traffic and a telephone survey both indicated that the program was only minimally effective, reaching the attention of only about half the families with children despite extensive advertising. Effects of the program on seat belt use closely paralleled the airing of radio announcements, appeared to have been confined mainly to children under age 4, and tapered off somewhat after the initial response. Table, figure, and 24 references. (Author abstract modified)