This study concerns the ecological and economic features of a particular category of complementary foods in ethnic Peru—comprising of insects, crustaceans, snails, and mushrooms— grouped as chitin-bearing foods (CBFs). Data collection was through participatory methods and semistructured interviews with 242 individuals in eight communities/villages from four ethnic populations. We found that, in Peruvian Amazonian Amerindian communities, CBFs are the most relevant protein source during the rainy season. Shrimp (Macrobrachium sp.), crab (Hypolobocera peruviana), palmweevil (Rhynchophorus palmarum), leaf-cutter ants (Atta cephalotes), and Lepidoptera larvae are common in the Amazonian diet. In Awajún and Ashaninka communities, most interviewed subjects declared significant consumption of CBFs, while a low percentage ate vertebrates every week during the rainy season and even in the dry season. In contrast, highland Quechua people occasionally consume larvae of Lepidoptera and Coleoptera and Quechua-Lamas populations (in the Amazonian region from historical times) consume the most accessible CBFs on a weekly basis. Traditional technologies and methods of semi-cultivation are evidence of a growing economic interest for CBFs. Relevant species have a high nutritional value in terms of chitin, fatty acids, and proteins, as well a high acceptance by the indigenous population. We conclude that Amazonian Amerindians manage these foods not only as a remedy for food shortage during the rainy season, but also as a stable forest resource and year-round agricultural by-product. We conclude that these traditional food practices should be incorporated within local and national agri-food policies to develop their economic potential and bring their social benefits into rural and peri-urban areas of Peru.