Honey samples were collected from 22 European and 22 Africanized honey bee colonies. The pollen from these honey samples was acetolysed and subsequently mounted on slides using glycerine jelly in order to identify frequently used nectar sources for honey bees in the Yucatan Peninsula during the wet and dry seasons. The most common species in order of abundance in the honey samples were: Metopium brownei, Mimosa bahamensis, Samyda yucatanensis, Thouinia caneseeras, Lonehoearpus rugosus, Bursera simaruba, Trema mierantha, Gymnopodium floribundum, Lonehoearpus sp. 2, Paullinia sp.1 and Viguiera dentata. Many of the pollen grains found in the honey samples were not from nectariferous plants, but from plants that produce pollen only: Cecropia peltata, several Cyperaceae, Gramineae and one Piperaceae. Families represented by the greatest number of species were: Leguminosae, Compositae, Gramineae, Malvaceae, Sapindaceae, Myrtaceae, Palmae, Polygonaceae, Cyperaceae and Sapotaceae. A comparison was made between the numbers of pollen and nectar flowers visited by bees from European and Africanized colonies in different apiaries. Less than 50% of the pollen species were common to both European and Africanized honey samples, indicating a differential utilization of the resources available Inglés