Genetic factors are likely to be the primary determinants of the cancer seen in around 5 - 10 % of all cancer patients. More than 20 inherited cancer syndromes are now known. For many of these cases molecular genetic diagnostic may be accomplished. Within the scope of genetic counselling and testing, which can validate the genetic background of cancer, the interdisciplinary cooperation of Primary Care Physicians (PCP) and human geneticists is necessary. The results of our empirical study on risk identification in familial cancer suggest that PCP in the acute care inform cancer patients only to a little extent about the possible genetic background of their disease. PCP also very rarely initiate genetic counselling and testing, which would be desirable for preventive reasons.