Food safety is a global concern for public health and the food industries. Microbial contamination can cause foodborne diseases and deterioration, generating important economic, social, and environmental consequences. Most conventional decontamination methods are associated with high temperatures, can induce result in microbial resistance. One promising alternative method is photodynamic inactivation (PDI), which involves administering a photosensitizer, followed by doses of visible light of an appropriate wavelength that generates singlet oxygen and free radicals that are toxic to target cells. This technique has been shown to be effective against a wide range of microorganisms. The aim of the present study was to evaluate the in vitro sensitivity of S. aureus ATCC 25923 to PDI using curcumin as photosensitizer. One aliquot (50µl) of bacterial suspension at 107CFU/ml was homogenized with 950µl of curcumin a concentration 7,510-7M and kept in the dark for 10 minutes. After incubation, 500µl of each sample was placed into flat-bottom wells and illuminated using a blue led (470nm) for 10 and 20min. The antibacterial effect of photosensitization on S. aureus was evaluated by the drop plate method. Appropriate dilutions of the treated samples and control groups (without illumination) were inoculated on trypticase soy agar plates and incubated at 37°C/24 h. The surviving cell populations were expressed as log CFU/ml. The experiment was performed in triplicate. The results showed a reduction of 4,25 and 4,42 logs CFU/ml for 10 and 20 minutes of illumination, respectively. Some factors may have interfered in the activity , such as photobleaching due to long exposure to light or agregation of curcumin with the diluent. The study demonstrated that the use of natural substance associated photosensitization process is reduction potential of S. aureus ATCC 25923, may be used for food preservation.