This review article discusses recent advances in the chemistry and plant origin of propolis, a sticky substance collected by bees from plants. Propolis has been used for centuries for its medicinal properties, including antibacterial, antifungal, and antiviral effects. The article reviews new information on propolis constituents published since 1995, focusing on the chemical composition and biological activity of propolis from native South American stingless bees. It also discusses the plant sources of bee glue, emphasizing data based on reliable chemical evidence, including comparisons between propolis samples and plant material. The article highlights the variability of propolis composition depending on the plant sources and geographic location, which poses challenges for its chemical standardization. The main plant sources of propolis in temperate regions are bud exudates of Populus species and their hybrids, while in tropical regions, sources include Cistus spp., Ambrosia deltoidea, and Clusia species. New compounds identified in propolis include flavonoids, prenylated p-coumaric acids, acetophenones, lignans, diterpenes, and volatile compounds. These compounds exhibit various biological activities, including antibacterial, cytotoxic, and immunomodulatory effects. The article also discusses the chemical composition of geopropolis, a type of propolis produced by stingless bees in tropical South America, and highlights the importance of understanding plant sources for the chemical standardization of propolis. The review concludes that further research is needed to determine the chemical composition and biological activity of propolis in different geographic regions, which could lead to the development of standardized "local" propolis types based on plant origin.This review article discusses recent advances in the chemistry and plant origin of propolis, a sticky substance collected by bees from plants. Propolis has been used for centuries for its medicinal properties, including antibacterial, antifungal, and antiviral effects. The article reviews new information on propolis constituents published since 1995, focusing on the chemical composition and biological activity of propolis from native South American stingless bees. It also discusses the plant sources of bee glue, emphasizing data based on reliable chemical evidence, including comparisons between propolis samples and plant material. The article highlights the variability of propolis composition depending on the plant sources and geographic location, which poses challenges for its chemical standardization. The main plant sources of propolis in temperate regions are bud exudates of Populus species and their hybrids, while in tropical regions, sources include Cistus spp., Ambrosia deltoidea, and Clusia species. New compounds identified in propolis include flavonoids, prenylated p-coumaric acids, acetophenones, lignans, diterpenes, and volatile compounds. These compounds exhibit various biological activities, including antibacterial, cytotoxic, and immunomodulatory effects. The article also discusses the chemical composition of geopropolis, a type of propolis produced by stingless bees in tropical South America, and highlights the importance of understanding plant sources for the chemical standardization of propolis. The review concludes that further research is needed to determine the chemical composition and biological activity of propolis in different geographic regions, which could lead to the development of standardized "local" propolis types based on plant origin.