Transfusion of a bacterially contaminated blood product can have serious consequences. We undertook an electronic survey of representative Canadian hospitals to determine current clinical and laboratory practices for investigating such reactions, prior to the development of national guidelines. There was considerable variability in symptoms and signs that would trigger investigation of possible contamination. The most frequent laboratory investigations performed were aerobic blood cultures of recipients and the residual component. If there is no residual product in the component bag, 36% of respondents would use a segment to perform testing. Guidelines could be helpful in improving and standardizing these practices.