Recent discussions in language communication indicate the effectiveness of technology and computer-mediated communication. Research also highlights the central role of synchronous and asynchronous modes of interaction in second and foreign language development. Gaining insights from Vygotskyan sociocultural theory of mind, the present study employed a mixed methods approach to explore the effect of synchronous computer-mediated corrective feedback on EFL learners' grammatical knowledge development. The participants were 40 Iranian EFL learners selected through a grammar-based pretest. Employing Skype software, the experimental group (N=20) was exposed to online text-based chatting. The purpose was to provide the participants with online technology-based corrective feedback on their grammatical errors. However, the control group (N=20) did not receive technology-enhanced corrective feedback during the experiment. The results highlighted: (a) the technology-enhanced, experimental group outperformed their counterpart with regard to grammatical accuracy, (b) the online Skype-based text chatting context played a mediating role in reinforcing the experimental group's grammatical knowledge, and (c) the participants displayed a high level of motivation to initiate and engage in L2 communication. The participants' experience of the Skype-based classroom emphasized themes of overcoming emotional problems in communication and fostering interpersonal relationship and rapport with the teacher and peers. Pedagogical implications focus on the potential of synchronous computer-mediated communication-based contexts as useful spaces for active collaborative learning and task engagement.