BACKGROUND Haemopoietic stem cells can be collected from a donor either as a bone marrow harvest or by peripheral blood collection. Both techniques have risks for the donor. OBJECTIVE The aim of this review was to identify the adverse effects of haemopoietic stem cell donation and to compare the tolerability and safety of the two methods. METHODS We searched bibliographic databases including the Cochrane Central Register of Controlled trials (CENTRAL) (The Cochrane Library 2008, issue 2), MEDLINE and EMBASE up to May 2008. We also searched reference lists of articles and contacted experts in the field. METHODS Randomised controlled trials enrolling haemopoietic stem cell donors and evaluating the different methods of donating haemopoietic stem cells were eligible. METHODS Two authors independently screened studies for inclusion. We extracted data and evaluated methodological quality. Quantitative analysis was not possible for most outcomes, but where used we preferred random-effects models due to the variability between the included studies. RESULTS Six trials (807 donors) were eligible: all were substudies, or constituent parts of, larger randomised controlled trials of bone marrow and peripheral blood stem cell allogeneic transplantation. No included trial was designed solely to measure and assess the experience of stem cell donors. The donors in all studies were related to the stem cell recipient. Overall, both types of donors experienced pain subsequent to donation, and psychological morbidity. The trend was for bone marrow donors to experience more pain at the donation site, more overall adverse events, and more days of restricted activity. They were also more likely to require hospitalisation than peripheral blood stem cell donors. In contrast, peripheral blood stem cell donors experienced more pain prior to donation, which may be related to the pre-donation administration of granulocyte colony stimulating factor (G-CSF). The methodological quality of the studies was poor and indicated limitations due to the risk of selection and attrition bias. The proportion of donors from the parent trial not included in the donor substudies was also inadequately explained. CONCLUSIONS The different short-term morbidities associated with each type of haemopoietic stem cell donation were clear, with bone marrow donors experiencing more pain and more restriction post-donation than peripheral blood donors. However, the studies were limited by their methodological quality, failure to provide long-term follow up (for which larger numbers of donors would be required) and a failure to apply consistent measures of quality of life in a way which allows more meaningful evaluation across studies.