Genetic testing for susceptibility for common cancers is widely available. Thus, doctors have a role in identifying and referring patients who would benefit from a consultation with a specialist in genetics. This study aims to assess doctors' referral rates, knowledge and attitudes towards cancer genetic testing, broken down by specialty (gastrointestinal, breast/ovarian, other specialties and General Practitioners-GPs). A 4-page questionnaire was mailed out to the GPs of all patients seen in 2012 in the Hereditary Cancer Clinic of St. Vincent's Hospital Sydney (n = 128) and all the specialists in St. Vincent's Hospital Sydney that might refer to the HCC (n = 33). 50 questionnaires were returned (31 %). Most doctors had referred a patient for cancer genetic testing (90 %). The average proportion of patients referred was 1 in 68.5 patients with breast/ovarian specialists referring the most, followed by gastrointestinal specialists and GPs. There was suboptimal knowledge of cancer genetic testing amongst doctors. Breast/ovarian specialists were most knowledgeable, followed by gastrointestinal specialists, other specialists and GPs. There were indications of inappropriate referral amongst doctors. Most (77.6 %) doctors were willing to receive further information on cancer genetics. Nearly all (94 %) doctors believe that it is their duty to inform an individual at high risk for hereditary cancer that cancer genetic counselling and testing is available. The majority of doctors have positive attitudes towards cancer genetic testing. Defective knowledge scores, however, indicate that doctors need further training or tools to enable them to refer patients appropriately for cancer genetic testing.