Aeromonas hydrophila and Campylobacter jejuni are bacteria of emerging importance in public health. However, little has been published about fish contaminated by these pathogens. The present study aimed to verify the presence of Aeromonas hydrophila and Campylobacter jejuni in fresh tuna samples (Thunnus spp.) caught off the coast of Santa Catarina State and distributed in the wholesale market of São Paulo/SP. A total of 85 tuna fillet samples were collected and examined by PCR and bacteriological analyses. Aeromonas spp. was detected in 11/85 (13%) samples, with 10/11 (90.9 %) being confirmed as Aeromonas hydrophila by PCR. Campylobacter spp. was found in 10/85 (11.7%) samples, 10/10 (100%) identified as Campylobacter jejuni by PCR and conventional biochemical analyses. Both pathogens were found in 2/85 (2.3%) samples. This is the first report on the contamination of fresh tuna by Campylobacter jejuni and Aeromonas hydrophila in Brazil. In addition to show that tuna can be a vehicle for transmission of pathogens when consumed raw, it emphasizes the importance of further studies to support the control these pathogens in fish.