The authors randomly assigned 5th- and 8th-grade students to 1 of 3 treatment conditions to study the effects of frequency of exposure to an antismoking public service announcement (PSA) on the students' intent to smoke over time. They found that, among younger children only, viewing an antismoking PSA at least once reduced smoking intentions, although these positive effects did not remain over time. However, the antismoking PSA was effective for younger at-risk children. After younger at-risk children viewed the antismoking PSA once, their intent to smoke decreased significantly. Notably, these positive effects remained stable over time and mirrored the smoking intentions of younger children who were not identified as at risk.