The ultimate goal of reading is to construct text meaning based on visually encoded information. Essentially, it entails converting print into language and then to the message intended by the author. It is hardly accidental, therefore, that, in all languages, reading builds on oral language competence and that learning to read uniformly requires making links between a language and its writing system. As a system of communication, moreover, languages vary in their meaning-making conventions and methods of signaling those conventions. Writing systems also vary in what they encode and how they end it. It is thus essential to clarify how reading subskills--and their development--are altered by the properties of a particular language and its writing system. A small but growing body of evidence suggests that systematic variations do exist in literacy learning and processing in diverse languages. These variations have critical implications for theories of second language (L2) reading because, unlike first language (L1) reading, it involves two languages. The dual-language involvement implies continual interactions between the two languages as well as incessant adjustments in accommodating the disparate demands each language imposes. For this reason, L2 reading is crosslinguistic and, thus, inherently more complex than L1 reading. To deal with these complexities, L2 reading research must incorporate three basic facts about reading development in both theory formation and empirical validation: (a) reading is a complex, multifaceted construct, comprising a number of subskills; (b) the acquisition of each subskill necessitates distinct linguistic knowledge; and (c) in L2 reading, subskills development involves two languages. Consequently, the primary objective of this article is to clarify--through a systematic synthesis of research in reading and L2 acquisition--the specific ways in which L2 reading is constrained by language-specific demands both within and across languages.