The Marbled Wood-Quail feeds mainly on seeds, fruits, and small invertebrates, including earthworms, insects, harvestman (Opiliones), spiders, scorpions, centipedes, and millipedes (Schubart et al. 1965, Haverschmidt 1968, Stiles and Skutch 1989). Insects in the diet include Blattaria, Coleoptera (Elateridae, Geotrupidae, Staphylinidae, and Tenebrionidae), Diptera (larvae), Hemiptera, Hymenoptera (Formicidae: Pachycondyla; Termitidae), and Lepidoptera (larvae).
It is primarily a ground forager, scratching away at leaf litter. They usually feed socially in groups, but rarely fight over food (Skutch 1947).