In this paper I am concerned with risk–benefit analysis; that is, the comparison of the risks of a situation to its related benefits. We all face such situations in our daily lives and they are very common in medicine too, where risk–benefit analysis has become an important tool for rational decision-making. This paper explores risk–benefit analysis from a logical point of view. In particular, it seeks a better understanding of the common view that decisions should be made by weighing risks (...) against benefits and that an option should be chosen if its benefits outweigh its risks. I devote a good deal of this paper scrutinizing this popular view. Specifically, I demonstrate that this mode of reasoning is logically faulty if “risk” and “benefit” are taken in their absolute sense. But I also show that arguing in favour of an action because its benefits outweigh its risks can be valid if we refer to incremental risks and benefits. (shrink)