Background In 2006, Australia introduced graphic cigarette packet warnings. The new warnings include one of 14 pictures, many depicting tobacco-related pathology. The warnings were introduced in two sets; Set A in March and Set B from November. This study explores their impact on smokers' beliefs about smoking related illnesses. This study also examines the varying impact of different warnings, to see whether warnings with visceral images have greater impact on smokers' beliefs than other images. Methods Representative samples of South Australian smokers were interviewed in four independent cross-sectional omnibus surveys; in 2005 (n = 504), 2006 (n = 525), 2007 (n = 414) and 2008 (n = 464). Results Unprompted recall of new graphic cigarette warnings was high in the months following their introduction, demonstrating that smokers' had been exposed to them. Smokers also demonstrated an increase in awareness about smoking-related diseases specific to the warning messages. Warnings that conveyed new information and had emotive images demonstrated greater impact on recall and smokers' beliefs than more familiar information and less emotive images. Conclusions Overall graphic pack warnings have had the intended impact on smokers. Some have greater impact than others. The implications for policy makers in countries introducing similar warnings are that fresh messaging and visceral images have the greatest impact.