Domestic cats pose a latent threat to wildlife in natural and urban ecosystems. Both intrinsic (age, weight, sterilization status, etc.) and extrinsic factors (night confinement, interaction time with owners at home, etc.) can influence the number of prey items caught by cats. We address the fauna predation by domestic cats in three cities on the coast of Ecuador. Two objectives were established: (i) determine the richness, composition, abundance, and conservation status of the prey captured by domestic cats, and (ii) identify the intrinsic and extrinsic factors that influence the quantity of prey captured. A citizen science approach was employed to gather information about wildlife species caught and brought home by 100 cats in 50 households between March and October 2023. Cats captured 132 prey items, of which 53.8% were invertebrates, 27.3% reptiles, 8.3% birds, 6.8% mammals, and 3.8% amphibians. These prey items belonged to 53 taxa, 56.6% native and 15.1% non-native. Non-native reptiles Hemidactylus sp. and Anolis sagrei were the most frequently captured taxa, and ten native taxa were among the most commonly captured, particularly odonates. This is the first study to register predation of cats on amphibians in northwestern South America. The capture by cats of Coniophanes dromiciformis, a vulnerable and probably endemic snake, is noteworthy. Three factors—age, nocturnal confinement, and the presence of toys in their homes—were the most important factors that contributed to predation events. We recommend these factors be considered to reduce the impacts by owned cats on wildlife.