Socio-Cultural Theory, based on Vygotskian thought, is a theory about the development of human cognitive and higher mental function. The theory specially emphasizes the integration of social, cultural and biological elements in learning processes and stresses the socio-cultural circumstances’ central role in human’s cognitive development. Second Language Acquisition is concerned with the process of how a new language other than the native language is acquired and how much this is affected by other disciplines, among which is Socio-Cultural Theory. This theory facilitates reflection on some of the problems on second language acquisition from a new perspective. In addition, this new perspective provides some pedagogical implications for foreign language teaching. This article makes attempts to elucidate Social-Cultural Theory’s constructs, its influence on second language acquisition and the pedagogical implications for foreign language teaching.