Brucellosis is a zoonosis caused by bacteria of theBrucellagenus. Any source of contamination that could be infectious must be monitored to reduce the risk of exposure to brucellosis, so the purpose of this work was to determine the presence ofBrucellaspp. on surface water and tilapia (Oreochromis niloticus) skin from a volcanic lake in Mexico. A seasonal sampling during 2016-2017 was carried out at fifteen specific sites for water sampling and five sites for the collection of tilapia fish. From all water and fish samples tested, we found only three isolates ofBrucellaspecies. We isolated and identifiedB. abortusfrom surface water through bacteriological and molecular techniques, andB. abortusandB. suisfrom the same tilapia skin sample. The isolated strains likely came from breeding animals that are common to the region, such as infected pigs or cattle withBrucella abortusorB. suis, respectively. A similar finding has not been reported in a water from volcanic lake or tilapia fish in Mexico. We concluded thatB. abortusandB. suisare present on the surface water of the volcanic lake and tilapia skin as possible contaminants derived from biological material from cows and pigs carrying this bacterium.