New technologies and more research in genetics have revealed an increasing amount of genetic data and identified new diseases. In parallel to the wider availability of genetic testing, efforts have been made to regulate the use of genetic technology and genetic information. The swift pace of developments, not surprisingly, may cause uncertainty among those confronted with genetics. The authors review the current state of genetic testing with a focus on movement disorders. They introduce terminology (inheritance patterns; penetrance; clinical and genetic heterogeneity and types of testing, including influences of direct-to-consumer testing) and discuss general aspects of genetics, including indication for testing, familial implications as well as social, ethical, and in particular legal implications (discrimination acts, insurance aspects, protection of data of deceased, etc.). They also cover recent developments with regard to new molecular techniques, economic issues, and the difficulties of data interpretation.