In this article, the author focuses on the allocation of decision-making authority between parents and physicians. She argues that parents should have substantial room to decide whether genetic testing is good for their child and that they may appropriately consider interests in addition to those of their child in making such choices. A physician, however, may refuse to act pursuant to parental views about testing, when in the physician's view, the parents' choices would pose a risk of significant harm to the child. The balance of control between parents and physicians is illustrated by discussion of a series of case vignettes. Refusal to perform requested testing is most often warranted for testing for carrier status and for genetic predisposition to late onset disease. The author concludes her analysis by discussing why it is appropriate to give increasing deference to the views of the child as the child grows older.