Traditionally genetic counselling has promoted a non-directive approach to patients' decision-making but the feasibility of this has been questioned. Unlike most branches of medicine, which are shifting away from a paternalistic model, genetic counselling is approaching shared decision-making from a different perspective. There are certain features of genetic counselling and genetic testing which may complicate the drive towards shared decision-making and informed choice: 1. Genetic test results can have broader implications than non-genetic test results. 2. Genetic test results may be perceived by the patient differently to non-genetic test results. 3. Carrier status for autosomal recessive conditions may be difficult for patients to conceptualize. 4. Decisions in genetic counselling are often multiple and sequential. 5. Most information in genetic counselling is based on probabilities and uncertainties. Each of these features is discussed in relation to achieving shared decision-making in genetic testing and the implications for genetic counsellors are described. The points raised, however, have broader implications for medicine as several of the features, although central to genetic testing, are not entirely unique. Lessons learnt from genetic testing and genetic counselling in achieving shared decision-making could help develop methods of promoting informed choice in other medical arenas such as cancer screening.