The present study was to evaluate the bactericidal effects of biocides on Bacillus sp. biofilm formed on stainless steel. Tests were performed using different concentration of biocides, biofilms of 6 day old and a range of exposure times (from 0 (control) to 1, 5 and 20 minutes). The results provide clear evidences of resistance to detachment of Bacillus subtilis and Bacillus cereus attached to stainless steel, and for all the situations studied, bacterial biofilms were not completely removed (being still active) after biocide treatment.