We quantified the diet of the Rufous-legged Owl (Strix rufipes) by analysing 63 pellets collected during 2003 and 2005 in a small coastal sclerophyllous forest stand at the northern limit of its distribution in Chile (31–32° S). The diet comprised small mammals (frequency = 57.8%, biomass = 99.3%), crustaceans (frequency = 1.7%, biomass = 0.1%), and insects (frequency = 40.5%, biomass = 0.6%). We identified at least 10 small mammal species in these pellets of which Bennett's chinchilla rat (Abrocoma bennetti; frequency = 12.4%) and long-tailed pygmy rice rat (Oligoryzomys longicaudatus; frequency = 7.4%) were the most frequently occurring mammalian prey remains. Terrestrial small mammals accounted for 21.5% by frequency of all individuals and 49.1% of the total biomass; scansorial/arboreal small mammals accounted for only 13.2% of all individual prey and 17.2% of total biomass.