Working memory (WM) refers to our cognitive capacity to temporarily and simultaneously store and process a limited amount of information in our mind to complete ongoing mental tasks. Extending previous studies applying cognitive WM models and perspectives, in this chapter we argue that an alternative approach, namely, affective WM, may be able to shed new light on WM-task-based language teaching (TBLT) explorations. To this end, we propose to incorporate an affective working memory (AWM) perspective on conceptualizing and measuring WM in second language acquisition (SLA) and TBLT research. In line with this proposal, we first elaborate on the affective WM theories and measurement procedures and demonstrate their potential implications for TBLT research. We then move on to discuss the design and construction of some sample AWM tests that can be readily implemented in future TBLT research. Overall, we argue that affect and emotion are essential parts of mental representations held in WM that are likely to influence second language (L2) processing and acquisition in TBLT.