The advent of CLT in the 1980s led to the CLT-SLA debate which continued unabated for the last forty years. This paper asks, Does the now dominant Communicative Language Teaching (CLT) promote Second Language Acquisition (SLA)? In addressing this question, the paper first reviews and explains the social academic history of CLT; different versions of CLT (strong, weak); how CLT operates; its relationship to SLA, such as perceptions of SLA that have contributed to the development of CLT pedagogy (communicative competence, input, output, interaction hypothesis); and techniques used in CLT. Next, it deliberates on the most controversial issues of the CLT-SLA debate, including language forms, corrective feedback, teachers' perceptions of and approaches to CLT, and classroom conditions, followed by a discussion of the ease/difficulty of implementing CLT. It concludes with a discussion of how teachers can best practice CLT in their classrooms.