The guidelines of the Brazilian National Health System (SUS) state that the municipal authorities are responsible for the vaccination of the population. The present study examined the types of immunobiologicals, amounts and reasons for their destruction and disposal by the Municipal Health Secretariat in the city of Bauru, São Paulo state, Brazil, between 2008 and 2009. This study comprises a descriptive, exploratory and retrospective work that employed search of bibliographic data, collection of secondary data from forms of immunobiologicals disposal and interview of the agent responsible for the disposal of these products in the municipality. It was observed that the total numbers of unused vaccines in 2008 and 2009 were similar (4523 and 4395, respectively), being the most discarded: the diphtheria, tetanus and pertussis (DTP) vaccine in 2008 and DTP, BCG and influenza in 2009. It was found that the amount of discarded vaccines could be reduced since the reasons for that were predictable. Moreover, the current study emphasized that although there is a municipal regulation for the disposal of immunobiologicals, the city still requires a better structure to handle such problem.