The inhibitory effect of a bacteriocin, produced by Pediococcus acidilactici, against Listeria monocytogenes and Clostridium perfringens on Spanish raw meat surface, was evaluated by in situ assays. Samples were incubated with the bacteriocin and then with a culture of the pathogenic bacteria. The treatment with 500, 1000 or 5000 bacteriocin units/ml (BU/ml) reduced the counts of L. monocytogenes after storage at 15°C during 72h by 1, 2 or 3 log cycles and with 1000 or 5000 BU/ml after storage at 4°C during 21 days by 2.5 or 3.5 log cycles, respectively, compared to the control. With C. perfringens a bacteriostatic effect could be observed.