The development of genetic tests marketed and sold direct-to-consumers (DTC) via the internet raises moral concerns and debate about their appropriateness and ethical and clinical significance. These tests are offered for a wide range of diseases and conditions, and the mutations have variable penetrance and associated risk. A number of these tests lack data on their accuracy and reliability, making interpretation of results difficult. DTC genetic testing is undertaken outside the context of the physician-patient relationship and may lack appropriate individual and family genetic counseling, leaving the consumer vulnerable to potential harms, such as misinterpretation of results, including false positive or false reassurance, with limited or no benefits. Beauchamp and Childress's four principles of biomedical ethics provide a framework for analyzing the ethical issues raised by DTC genetic testing. We argue that the potential harms outweigh the potential benefits of such tests, that respect for autonomy should be limited in light of potential harm from DTC testing, and that the availability of genetic testing over the internet may be considered unfair and unjust and affect resource allocation by placing an unfair burden on primary care physicians. In light of the moral issues posed by these tests, practical responses are suggested in the areas of consumer education, medical education, and interaction with commercial companies.