Baddeley and Hitch proposed a fundamental framework for working memory in 1974, emphasizing its transiently activated memory aspect for performing various cognitive tasks. This concept of working memory is quite useful in understanding human cognitive processes and has been widely used in the fields of cognitive and developmental psychology and neuropsychology. The idea of working memory has also been introduced to consider cognitive rehabilitation for patients with brain damage. In the present review, we first described a current theoretical framework of working memory and then reported on recent studies on the conceptualization of working memory. We subsequently reviewed neural substrates of working memory subsystems, i. e., the phonological loop, the visuospatial sketch pad and the central executive. We further referred to the contribution of working memory in understanding various language-related symptoms in patients with aphasia, one of the major targets in the field of cognitive rehabilitation. Working memory plays a crucial role in the everyday life of brain damaged patients. Future research is warranted to focus on the improvement of deficient working memory in order to ameliorate clinical problems of brain damaged patients.