Over the past 20-plus years, the instructional approach referred to as "explicit instruction" has been increasingly mentioned as an instructional method in the learning disabilities literature. Explicit instruction is not a unitary intervention, but can be a combination of over a dozen teaching behaviors or components used to design and deliver instruction. This multicomponent aspect likely contributes to the variability of the descriptions and definitions of explicit instruction found in journals, books, and other published documents. Because explicit instruction has become a prominent and often discussed topic in special education, we attempt to define and describe the term more precisely in order to increase the clarity and consistency of its use in both research and practice. In addition, we expand our discussion to include a brief historical perspective of the evolution of explicit instruction from earlier programs and research efforts such as "Direct Instruction" and "direct instruction," as well as providing a summary of its effectiveness, especially for students with learning disabilities.