OBJECTIVE: Post-tonsillectomy pain is believed to be mediated by noxious stimulation of C-fiber afferents located in the peritonsillary space, and local anesthetic infiltration to this area may decrease pain by blocking the sensory pathways and thus preventing the nociceptive impulses. We aimed to compare the effects of different concentrations of preincisional peritonsillar levobupivacaine (0.25% and 0.5%) infiltration on postoperative pain and bleeding in a placebo-controlled design.