ABSTRACT: BACKGROUND:School-age children are important drivers of annual influenza epidemics yet influenza vaccination coverage of this population is low despite universal publicly funded influenza vaccination in Alberta, Canada. Immunizing children at school may potentially increase vaccine uptake. As parents are a key stakeholder group for such a program, it is important to consider their concerns. PURPOSE:We explored parents' perspectives on the acceptability of adding an annual influenza immunization to the immunization program that is currently delivered in Alberta schools, and obtained suggestions for structuring such a program. PARTICIPANTS:Forty-eight parents of children aged 5-18 years participated in 9 focus groups. Participants lived in urban areas of the Alberta Health Services Calgary Zone. FINDINGS:Three major themes emerged: Advantages of school-based influenza vaccination (SBIV), Disadvantages of SBIV, and Implications for program design & delivery. Advantages were perceived to occur for different populations: children (e.g. emotional support), families (e.g. convenience), the community (e.g. benefits for school and multicultural communities), the health sector (e.g. reductions in costs due to burden of illness) and to society at large (e.g. indirect conduit of information about health services, building structure for pandemic preparedness, building healthy lifestyles). Disadvantages, however, might also occur for children (e.g. older children less likely to be immunized), families (e.g. communication challenges, perceived loss of parental control over information, choices and decisions) and the education sector (loss of instructional time). Nine second-level themes emerged within the major theme of Implications for program design & delivery: program goals/objectives, consent process, stakeholder consultation, age-appropriate program, education, communication, logistics, immunizing agent, and clinic process. CONCLUSIONS:Parents perceived advantages and disadvantages to delivering annual seasonal influenza immunizations to children at school. Their input gives a framework of issues to address in order to construct robust, acceptable programs for delivering influenza or other vaccines in schools.