Advanced genomic analytical technologies are developing and challenging the current framework of clinical laboratory testing. However, most genomic tests have been devised as laboratory-developed tests (LDTs) without sufficient validation of their analytical validity. Quality assurance (QA) of tests is mandatory for routine clinical practice. External quality management systems such as ISO add QA. Other than QAs of pre-analysis, analytical procedures, reports, and laboratory personnel should be regularly assessed using appropriate best practices and guidelines for analytical validity. Moreover, ethical, legal, and social issues concerning genomic information should be resolved in genomic tests. Taken together, clinicians and health care policymakers must consider the accuracy with which a test identifies a patient’s clinical status and the risks and benefits resulting from test use. Genomic tests in current use vary in terms of their accuracy and potential to improve health outcomes. Recently, high-throughput analysis using next-generation sequencing and microarrays is being developed and introduced into clinical practice. As analysis of these data sets is a huge challenge, it requires novel analytical processes that include data quality assessment, comprehensive analysis, interpretation of the results, and presenting the results to users. Especially, human resources are required to develop genome informatics to interpret large amounts of data. Another issue is to regulate Direct To Consumers (DTC) genetic tests by medical institutions as a salutary health service. Although advanced genomic analytical technologies present some issues, they are useful and powerful tools in clinical practice. Thus, they will be properly introduced into clinical practices in a step by step manner.