There is interest in estimating familial cancer risks in clinical practice for counselling and determining patients' screening requirements. Empiric methods can be used to estimate an individual's risk, however, every family history is unique making such methods relatively non-specific. In contrast if an underlying genetic model can be assumed the risk of disease can be calculated for any individual using his or her family history. A method of estimating familial cancer risks based on segregation models and linkage data is presented and its implementation discussed.