OBJECTIVES: To describe the effects of communication partner training on persons with aphasia and their communication partners. Specifically the systematic review addressed 3 clinical questions regarding the impact of partner training on language, communication activity and participation, psychosocial adjustment, and quality of life for adults with aphasia and their communication partners. DATA SOURCES: Twenty-three terms were used to search 12 electronic databases (eg, PubMed, CINAHL, PsychINFO, PsychArticles, CSA Linguistics and Language Behavior Abstracts, Social Sciences Citation Index [Web of Science], SUMSearch, TRIP, EMBASE, REHABDATA, National Library for Health, Cochrane Database of Systematic Reviews) and the journal "Aphasiology." References from all relevant articles were hand-searched. STUDY SELECTION: Two reviewers independently applied inclusion criteria to select potential relevant articles from the titles and abstracts of references retrieved by the literature search. The full text of the remaining articles was reviewed by a 5-member panel, resulting in a corpus of 31 studies that met the final inclusion criteria. DATA EXTRACTION: Two independent reviewers extracted the descriptive data related to the participants, the intervention, the outcome measures, and the results. DATA SYNTHESIS: The 5-member review team by consensus classified the studies using the American Academy of Neurology system for classification of evidence (2004). CONCLUSIONS: Evidence shows that communication partner training is effective in improving communication activities and/or participation of the communication partner and is probably effective in improving communication activities and/or participation of persons with chronic aphasia when they are interacting with trained communication partners. There is insufficient evidence to make recommendations related to the impact of partner training on persons with acute aphasia or the impact of training on language impairment, psychosocial adjustment, or quality of life for either the person with aphasia or the communication partner.