Are assisted reproductive technologies (ARTs) a medical issue or a matter of public policy, subject to restrictions? Francesca Scala employs the concept of boundary work to explain the protracted debates that ensued when Canada appointed a royal commission in 1989 to settle the issue. She reveals that both sides of the debate attempted to secure their position as authorities by challenging, defending, or blurring the boundaries between science and politics. This compelling account contributes to our understanding of the interaction between science and politics, the exercise of social control over science and technology, and the politics of expertise in policy making.