The Gram-negative bacterium Stenotrophomonas maltophilia is frequently isolates from pharmaceutical facilities, especially in water systems (COSTA et al., 2017; SELIM et al., 2020). The biofilms formed by these microorganisms help them to acquire greater resistance to the action of physical and chemical agents, which may contribute to the prevalence of these pathogens in some environments. After biofilm formation, additional microorganisms can proliferate by aggregation and detach from the surface in different stages of the production chain. This event can limit the efficiency of random sampling in quality control and affect the release of a batch (PDA, 2015; VASCONCELLOS et al., 2021). This study aimed to evaluate the aggregative capacity and the structure of the biofilm by Scanning Electron Microscopy (SEM).