Many carnivores are sensitive to habitat fragmentation, and the capacity to shift diets may improve their ability to persist in urban areas. We collected and identified contents of a total of 119 scats from coyotes (Canis latrans), 58 scats from gray foxes (Urocyon cinereoargenteus), and 31 scats from bobcats (Lynx rufus) within habitat fragments of varying size in the San Diego area in coastal southern California. Coyote diet was generalist, composed of mostly mammals but also anthropogenic items, fruit and seeds, birds, and invertebrates. Dietary breadth of coyotes was similar in small urban habitat fragments and larger sites, but composition differed, suggestive of the opportunistic habits of coyotes. Notably, domestic cats occurred in 29% of coyote scats in small urban fragments, implicating coyotes as a threat to cats. Like coyotes, gray foxes had an omnivorous diet consisting of mammals, fruit and seeds, invertebrates, and birds. As with coyotes, dietary breadth of gray foxes was similar in urban habitat remnants and larger control sites. Bobcats, not detected in small urban fragments, had a more specialized diet focused primarily on mammalian prey. Such resource specialization might limit bobcats' ability to exploit anthropogenic subsidies and hence persist in small urban patches, compared to more opportunistic carnivores such as coyotes and gray foxes.