Propolis is a resinous natural substance collected by honey bees from buds and exudates of various trees and plants. It is widely accepted that the composition of propolis depends on the phytogeographic characteristics of the site of collection. In this study, we have analyzed the chemical composition of a propolis collected in Quintana Roo, Mexico, and evaluated its antioxidant, antifungal, and antibacterial activities. Unexpectedly, the chemical analysis showed that the main components of the ethanolic extract of this Mexican propolis appeared to be pentacyclic triterpenoids, such as α and β-amyrin derivatives, and sterols. The crude extract did not show antioxidant activity when tested using the DPPH-reduction assay, and it also proved inactive when tested for antifungal and antibacterial activities using microdilution and agar diffusion assays, respectively. The fact that the presence of both α and β-amyrins and their derivatives have been reported from the resin of Bursera simaruba, one of the plants used by the bees for propolis production in Quintana Roo, Mexico, confirms the relationship that exists between the flora available to bees in agiven region and the chemical composition of the propolis that they produce.