Although much progress has been recorded, tobacco smoking remains a major public health problem in the United States. Smoking is associated with a significant disease burden, substantial economic loss and nearly half a million deaths in the US annually. Individuals with a personal or family diagnosis of smoking related illnesses may be a priority audience for smoking cessation messages, not only because of the resulting health benefits, but also because their diagnoses may serve as cues to quitting smoking. At present however, it is not clear from the literature if the diagnosis of cancer or other smoking-related illnesses serve as significant cues to changes in smoking behavior, especially among individuals with heavy smoking history. The overall aim of this dissertation effort therefore was to assess, using elements of the Heuristic Teachable Moment Model of health behavior (McBride et al, 2003), whether cueing events – cancer diagnosis, heart or lung procedures, physician-diagnosed illnesses and self-reported symptoms - were associated with changes in smoking behavior in a cancer screening population with significant smoking history. In generalized logistic regression analyses adjusted for age and pack-years of smoking, we found that compared to persons with no reported history of cueing events, quit attempt odds ratio generally increased with increasing number of smoking-related adverse events. The relationship between successful quitting and cueing events was more complex; a history of heart or lung procedure was significantly associated with higher odds of successful quitting, cancer history and physician-diagnosed illnesses were not associated with successful quitting, while a history of self-reported symptoms showed a strong inverse association with successful cessation. The public health implications of these findings are discussed.