The consistent multi-ethnic migrations of the last decades have considerably changed the epidemiology of the hemoglobinopathies. Healthy carriers of these conditions are present today in many nonendemic parts of the world, and severely affected children are now born where these diseases were previously rare or unknown. Improving the competence in carrier diagnostics at the laboratory level is one of the first concerns when introducing management and primary prevention of the severe conditions in nonendemic areas. This review describes how and when carriers should be correctly diagnosed and informed. The essential technologies needed for basic carrier diagnostics in different situations are summarized in some detail, and interpretation of the results and a number of related problems are discussed. The role of the hematology laboratory is essential, particularly in nonendemic areas where the first line of health care is often insufficiently aware of hemoglobinopathy management. Carriers living in nonendemic areas can be appropriately diagnosed and informed regarding genetic risk and prevention by well-organized laboratories. Both basic and specialized diagnostics are needed for the correct treatment for the anemic carriers, for primary prevention in couples at risk and for state-of-the art care of severely affected patients.