The objective of this review was to summarize and critically evaluate the clinical evidence of the effect of qigong exercise on immunity and its efficacy in the prevention or treatment of infectious diseases. Thirteen databases were searched from their respective inceptions through January 2011, and all controlled clinical trials of qigong exercise on immunity and infections were included. Quality and validity of the included studies were evaluated using standard scales. Seven studies including two randomized controlled trials (RCTs), two controlled clinical trials (CCTs) and three retrospective observational studies (ROSs) met the inclusion criteria. One study focused on functional measures of immunity (antigen-induced immunity) and six studies on enumerative parameters of immunity. No study on clinical symptoms relevant to infectious diseases could be identified. Overall, the included studies suggested favorable effects of qigong exercise on immunity, but the quality of research for most of the studies examined in this review was poor. Further rigorously designed studies are required, which should adhere to accepted standards of methodology for clinical trials.