Ninety-two fecal samples were collected from leopards (Panthera pardus, n = 54), tigers (P. tigris, n = 19), and leopard cats (Felis bengalensis, n = 3) in Huai Kha Wildlife Sanctuary, Thailand; four samples that may have come from clouded leopards (Neofelis nebulosa) or Asian golden cats (Felis temminicki) were identified as from small to medium cats. Twelve samples were identified as from large cats. Samples preserved in 10% formalin were examined for parasite eggs, larvae, cysts, and oocysts by centrifugal sugar flotation and sedimentation techniques. Ninety-six percent of all samples were positive, including 94% of the leopard, all of the tiger, clouded leopard, golden cat, and leopard cat samples. Diagnostic stages were identified from Paragonimus sp., Echinostomatidae, Dicrocoeliidae, Pseudophyllidea, Taeniidae, Mesocestoides sp., Hymenolepididae, Acanthocephala, Spiruroidea, Gnathostoma sp., Molineus sp., Ancylostomoidea, Mammomonogamus sp., Toxocara sp., Toxascaris sp., Me-tastrongyloidea, Capillaria spp., Isospora sp., Toxoplasma -like, Sarcocystis spp., and Giardia sp.