Advances in genetics have prompted recommendations that all healthcare providers perform genetic counseling and testing. Some experts are concerned about potential negative outcomes from cancer genetic testing performed without genetic counseling by certified genetics professionals. We report a national series of cases illustrating negative outcomes of cancer genetic testing performed without counseling by a qualified provider. Three major patterns emerged from analysis of these cases: 1) Wrong genetic test ordered, 2) Genetic test results misinterpreted, and 3) Inadequate genetic counseling. Negative outcomes included unnecessary prophylactic surgeries, unnecessary testing, psychosocial distress, and false reassurance resulting in inappropriate medical management. CONCLUSION: With the complexities of cancer genetic counseling and testing, it may be unrealistic to expect all clinicians to provide these services. A more realistic approach is better provider education and a framework in which healthcare providers identify patients who would benefit from a referral to a certified genetic counselor or experienced cancer genetics professional.