To date, there has been little experimental knowledge on the genetic risks of human exposure to ionising radiation for humans. Recent data suggest that hypervariable tandem repeat minisatellite loci provide a useful and sensitive experimental approach for monitoring radiation-induced germline mutation in humans. Here, I review the results of studies on minisatellite mutation rates in human populations exposed to radioactive fallout after the Chernobyl accident and nuclear weapon tests in Kazakhstan.