This paper addresses the dilemmas of participant sampling and recruitment for deliberative science policy projects. Results are drawn from a deliberative public event that was held in April and May, 2007. The research objective of The BC Biobank Deliberation was to assess deliberative democracy as an approach to legitimate policy advice from a subset of British Columbians concerning the secondary use of human tissues for prospective genomic and genetic research. The overall goal was to have participants identify key values that should guide a biobank in British Columbia. This paper assesses our team's group decision-making processes concerning participant sampling for the 2007 event. Results presented here should allow the reader to critically examine our team's choices and could also be used to assist advocates of deliberative democracy and others who may wish to propose similar events in the future.