Excessive risk-taking behaviors have been implicated as a potential endophenotype for substance use disorders and psychopathological gambling. However, the genetic and environmental influences on risk taking and the risk-related brain activations remain unclear. This study investigated the heritability of risk taking and the genetic influence on individual variation in risk-related brain activation. The Balloon Analogue Risk Task was used to assess individuals' risk-taking behavior. In a sample of 244 pairs of young adult twins, we found that there was a moderate heritability (41%) of risk taking. Using voxel-level analysis, we found a moderate genetic influence on risk-related brain activation. We also found a moderate genetic correlation between risk-taking behavior and risk-related brain activation in the left insula, right striatum, and right superior parietal lobule in the active-choice condition. The present study provides important evidence for the genetic correlation between risk-taking behavior and risk-related brain activation.