Direct Instruction (DI) is a powerful instructional approach designed to ensure that students master critical skills and content required for more advanced learning. Although DI has existed since the late 1960s, there are many common misconceptions about the approach, its potential to enhance student learning and the way its proper implementation facilitates students' academic success. This book provides a systematic explanation of the Direct Instruction methodology and DI program design as it outlines a roadmap for teachers and school leaders on how to implement DI successfully. Divided into three main sections, the first section describes DI as a coherent and complete teaching-and-learning system that contrasts DI with lower case "di" or explicit instruction, which focuses on effective instructional delivery techniques. The second section provides a step-by-step guide to implementing DI. The third section is devoted to cautions about implementing DI. This section reinforces the notion that the physical possession of the DI curricula does not by itself lead to student success. Those who adopt DI need to ensure that it is implemented with fidelity for the benefit of their students who are reliant on them to provide them with the means to achieve their academic potential so they may lead healthy, productive lives.