Second Language Acquisition (SLA), as a sub-discipline in applied linguistics, is rapidly growing and changing (Ellis & Shintani, 2014). As such, it has yielded stirring issues on both naturalistic and instructed settings causing reviews and/or investigations by language researchers. This paper accordingly serves as a humble attempt at critically reviewing the related literature of instructed SLA particularly direct instruction as situated in the landscape of language teaching. Initially, the paper kicks-off with the essentials of direct instruction. It subsequently delves into the importance of such instruction, and this extends to the analysis of notably empirical studies conducted in the 20th century and currently empirical studies in the 21st century. In regards of these, the paper arrives at conclusions, recommendations, and trajectories for future SLA studies.