Focal brain stimulation to enhance human cognitive and language functions in both healthy individuals and those with aphasia is a relatively new and exciting area of research. In this special issue leading authors in the field present novel data and summarize the evidence related to the use of transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS) and epidural cortical stimulation. These techniques are used not only for understanding normal brain-language functions but also language learning and recovery after brain damage. The first brain stimulation trials in aphasia rehabilitation are then investigated along with suggested directions for future research.