The physical and psychosocial consequences for patients undergoing blood SCT for the treatment of cancer and their families have been extensively documented. There has, however, been far less investigation into the psychosocial consequences for sibling donors who are both family members and undergoing an invasive medical procedure. The aim of this study was therefore to explore the psychosocial impact of PBSC donation before, during and after donation, and to gain insight into donors' experiences of the preparation for, and procedures associated with, donation. Participants included 13 men and 9 women, with a mean age of 53.1 (SD=9.4) years, who underwent PBSC or BM donation between 2007 and 2010. Data were collected via face-to-face or telephone interviews and a questionnaire. Results revealed that a broad range of both positive and negative emotions were experienced at different time points during donation. The psychosocial impact of donation was also influenced by the interactions between factors such as pragmatic aspects of the donation process; family dynamics; perceived adequacy of preparation and emotional support; and uncertainty related to health outcomes for the recipient and donor. Routine provision of psychosocial support to donors as well as recipients is therefore important.