The aim of this article is to analyze the role of the distinction between principle and constructive theories in the question of the explanatory power of special relativity. We show how the distinction breaks down at the explanatory level. We assess Harvey Brown's claim that, as a principle theory, special relativity lacks explanatory power. We argue that this claim is based on an unrealistic picture of the kind of explanations provided by principle (and constructive) theories. Finally, we argue that the structural account of explanation captures the explanatory success of special relativity. © 2011 by the Philosophy of Science Association. All right reserved.