A mass media campaign aired in the Australian state of Victoria aimed to increase awareness and encourage identification of the abdominal circumference for men and women that placed them at increased risk of cancer. The evaluation assessed the extent to which ad exposure was associated with improvement in awareness, intentions and behaviours with respect to weight and cancer. Respondents were overweight or obese adults aged 30-69 years and exposure to the advertisement occurred via commercial television programmes in a natural setting. Questionnaire assessment occurred before, immediately after and 2 weeks following exposure to the advertising, and a comparison group who did not recall the ad completed the same interviews. For the main analyses, the exposure group was those who recalled the advertisement at post-exposure and follow-up (n = 101). Those who did not recall it at either stage comprised the unexposed group (n = 81). The campaign achieved its primary objective of increased awareness of the link between obesity and cancer and the specific waist sizes indicative of risk, as well as increased behavioural intentions with respect to weight and cancer. However, it did not have an effect on self-awareness of weight status, perceived personal risk of cancer or weight loss behaviour.