The green sea urchin Strongylocentrotus droebachiensis is the dominant grazer in the rocky subtidal zone in eastern Canada and its local abundance largely determines the structure and dynamics of the coastal ecosystem. Predation has been cited as an important factor controlling populations of this species, although the evidence for this assertion is equivocal. In this review, I examine the effects of predators on the distribution, abundance and behaviour of S. droebachiensis at each life history stage and evaluate the potential for predatory control. I conclude that our understanding of interactions between this species and its predators is insufficient to support any generalizations about the role of predation in regulating populations. Carefully designed field and laboratory experiments are required to rigorously test hypotheses about the effects of predators under realistic conditions, and to identify critical life history stages. Numerical modelling is a promising but underutilzed approach in the study of sea urchin population dynamics and predator-prey interaction.