The aim of this study was to investigate the efficacy of the anticlostridial pediocin A from Pediococcus pentosaceus FBB61 to contain negative effects associated to Clostridium proliferation in broilers, through 2 subsequent investigations. In the first study, 36 Ross 508 broilers were divided into 3 groups and fed for 21 d as follows: the control diet (CTR), the control diet supplemented with supernatant filtrate of a culture of P. pentosaceus FBB61-2 (Bac-, isogenic mutant nonproducing pediocin A), and the control diet supplemented with supernatant filtrate of a culture of P. pentosaceus FBB61 (Bac+) containing pediocin A. Birds were challenged with 10(6) cells of Clostridium perfringens. In the second study, 216 Ross 508 broilers were allocated in 18 pens and divided into 3 groups fed the same diet for 42 d: a control group (CTR), a group challenged with 10(8) cells of C. perfringens (CP), and a group challenged with 10(8) cells of C. perfringens and receiving the control diet supplemented with P. pentosaceus FBB61 and pediocin A (PA). Broiler BW, ADG, ADFI, and feed conversion rate were measured throughout the studies. At the end of both experiments, an appropriate number of birds was killed and analyzed for necrotic enteritis lesions and microbiological examinations. In the first study, on d 9, ADG and BW were 20% higher for Bac+ compared with CTR and Bac-; on d 14, ADG was higher for Bac+ (+23%, P<0.05), whereas BW was higher for Bac+ and Bac- compared with CTR (+23 and +14%, respectively; P<0.05). In the second study, on d 14, ADG and BW were higher for PA compared with CTR and CP (+15% on average; P<0.05), whereas between 15 and 42 d, there was only a tendency toward a higher ADG for PA when compared with the CP group (+4%, P=0.08). Diet supplementation with pediocin A improved broiler growth performance during the challenge with C. perfringens and tended to restore the ADG depletion during the 42-d period.