Propolis, commonly referred to as "bee glue", has been well documented in literature as a remedy to fight infections including the viruses that cause herpes and HIV-1. Propolis is a resinous substance gathered by bees to line and reinforce their hives, and the antimicrobial properties of propolis have been shown to prevent microbial infection of bee larvae, honey stores, and combs. In our experiments, we further investigated the antiviral properties of propolis by inhibiting the replication Ty1, an active long terminal repeat (LTR) retrotransposon in the budding yeast, Saccharomyces cerevisiae. Ty1 retrotransposon replication shares many common steps with retroviruses that infect humans, including HIV, and therefore compounds that inhibit Ty1 have the potential to also inhibit retroviruses. Antiviral effects of ethanol-extracted propolis were tested on the Ty1 retrotransposon. Ty1 replication was measured in the presence of different concentrations and sources of propolis using a Ty1 retrotransposition assay. The Ty1 gene was tagged with a sequence designed to produce its own histidine. Thus, if retrotransposition occured uninterrupted, the yeast would be able to thrive on a His- plate. The retrotransposition frequency was calculated using the standard formula for calculating mobile elements transposition. Our hypothesis stated that propolis would decrease the retrotransposition frequency of Ty1 by interfering with the reverse transcriptase activities of Ty1 and thus lower the frequency of transposition. While the majority of the propolis samples had little effect on reducing the frequency of retrotransposition, as hypothesized, there was evidence of a reverse effect, i.e. an increase in the retrotransposition frequency of Ty1 in a few cases. While it is unclear why propolis did not impact the frequency of transposition as expected, it is clear that further studies, such as the mechanism of entry of propolis into the yeast cells and effect of propolis on the cells' reproductive growth period, would be needed to better understand this phenomenon.