One of the major issues in controlling serum cholesterol through dietetic intervention appears to be the need to improve patient adherence. To explore the many questions regarding barriers to, and motivators for, cholesterol-lowering diet adherence. We surveyed French general practitioners' dietetic practices for patients with hypercholesterolaemia, and looked at their patients' attitudes towards such an approach. We analysed 234 doctors' personal questionnaires and 356 patient self-survey questionnaires. Patients' reasons for not complying with the prescribed diet included: 'already having satisfactory food habits' (34.7%), 'unwillingness to suffer nutritional deprivation' (33.3%), 'difficulties to conciliate a diet with family life' (27.8%) and 'taking cholesterol-lowering drugs' (22.2%). Despite a generally good understanding by patients of doctors' recommendations, some discrepancies were seen between their respective declarations. While doctors largely thought that patients needed more explanation on why and how a diet can lower cholesterol (and avoid taking drugs), only 39.4% of patients declared needing this kind of information. Other discrepancies were observed concerning barriers to, and motivators for, patient adherence. Moreover, some dietetic rules appeared to be more difficult to comply with than others, e.g. 82.6% patients remembered they should 'eat more fish' but only 51.3% actually did so. Finally, physicians, as well as patients, displayed a lack of confidence in lipid-lowering diet efficiency. Improving patient education, especially concerning their perception of risk, as well as increasing the involvement of dieticians, are motivators to explore in order to improve adherence.