Composed of various native and non-native plants, the Brazilian flora in its biodiversity remains a potential food source. In this context, plant species known in Brazil as unconventional food plants (UFP) deserve to be highlighted. Moreover, information concerning the safety of consuming Brazilian UFP and their natural toxins is still scarce. Thus, we explore the current literature (2010–2020) to obtain information on toxicity, toxins, and undesirable effects associated with 14 Brazilian UFP. The following databases were used during the research: Scielo, Embrapa Agricultural Research Databases, Web of Science, Medline, PubMed (via the National Library of Medicine), and Scopus. We screened 561 articles, and 39 articles were selected for analysis. In vitro, in vivo, and ethnobotanical studies were included. When considering the edible parts of the plants, Araucaria angustifolia (Bertol.) Kuntze, Sterculia striata A. St.-Hil. & Naudin, Hymenaea courbaril L., and Platonia insignis Mart. presented no toxicity reports. Bixa orellana L., Spondias mombin L., Genipa americana L., Byrsonima crassifolia (L.) Kunth, and Caryocar brasiliense Cambess presented low toxicity. Studies have revealed that consumption of Solanum paniculatum L., Portulaca oleracea L., Mauritia flexuosa L. f., Pereskia aculeata Mill., and Psidium cattleianum Sabine deserve caution due to their natural toxins such as steroidal glycoalkaloids, steroidal saponins, flavonoids, oxalic acid, and indole alkaloids. This chapter will contribute to guarantee safe consumption, help minimize undesired complications, and provide a more complete knowledge of known natural UFP toxins.