The aim of this review was to identify adverse events of moxibustion as reported in the medical literature. Computerised literature searches were carried out in 14 databases. All articles reporting adverse effects of any type from moxibustion in humans were included, regardless of study design and publication language. The related journals and references in all located articles were manually searched for further relevant articles. Data were extracted and evaluated according to predefined criteria by three independent reviewers. Adverse events related to moxibustion treatment were reported in 4 randomised clinical trials, 1 controlled clinical trial, 2 uncontrolled observational studies, 13 case reports, and 1 prospective study. The most common effects identified in this review were allergic reactions, burns, and infections such as cellulitis and hepatitis C. Allergic reactions were reported in six case reports (four case reports related to infections and two related to burns). The other articles were case reports of xerophthalmia, xeroderma, hyperpigmented macules, ptosis and eversion of the eyelids. In clinical trials, various adverse events such as rubefaction, blistering, itching sensations, discomfort due to smoke, general fatigue, stomach upsets, flare-ups, headaches, and burns were reported. Tenderness and pressure in the epigastric region or in one of the hypochondriac regions, unpleasant odour with or without nausea and throat problems, abdominal pain, premature birth, premature rupture of the membrane and bleeding due to excess pressure on the anterior placenta were reported in pregnant women. Moxibustion is not entirely risk free, as it has several kinds of potential adverse events such as allergy, burn and infection. Currently, the incidence of such events is not known. In the interest of patient safety, sufficiently large prospective studies should be considered to clarify this issue. Copyright © 2010 Elsevier Ltd. All rights reserved.