Objectives: To elicit predictors of variation in likelihood to purchase foods rich in long-chain omega-3 fatty acids. Design, setting and subjects: Responses from a community sample (n 5 220) were elicited using a computer-administered questionnaire based on an adaptation of Protection Motivation Theory including measures of perceived risk and vulnerability to coronary heart disease (CHD). Other measures included health status, body mass index (BMI), perceived risk/benefits of novel technologies and sociodemographics. Descriptions of model products were presented, including farmed fish fed fishmeal (FFFF); farmed fish fed genetically modified (GM) oilseed (FFFGM); bread, milk and supplements containing fish oil (SFO) or GM oilseed. It was hypothesised that perceived vulnerability to CHD would enhance acceptance of GM products (H1). Furthermore, information describing the benefits of LCO3FA, limitations to fish supply and potential alternatives was given to a treatment group (50%) and hypothesised to have a positive effect on the acceptance of GM products (H2). Results: No evidence was found to support H1 or H2. FFFF was most likely to be purchased (P , 0.01), followed by SFO and FFFGM. Multivariate regression analysis identified significant (P , 0.05) predictors (standardised b) for likelihood to purchase FFFF: self-efficacy 0.56; behaviour (product) efficacy 0.19; belief that fishmeal is unnatural 20.14 (R 2 5 0.44) and for FFFGM: self-efficacy 0.65; perceived severity of CHD 0.15; BMI 20.13; significant other has/had arthritis 0.11; belief that GM oilseed is unnatural 0.11 (R 2 5 0.49). Conclusions: Self-efficacy (confidence to consume) was the most important predictor of likelihood to purchase all products.