Brucellosis is a zoonotic infectious disease that represents serious economic and health problems. It has been extensively studied in different species of livestock but literary references to fish brucellosis are scarce. Therefore, the purpose of the research hereby presented was to investigate the serologic-bacteriologic response of Nile catfish to experimental infection with brucellosis. Thirty predatory catfishes were used. They were divided into two groups. The first was subjected to s. c. infection with Brucella melitensis biovar 3, the other to s. c. application of physiological solution. Three fishes from each group were killed once a week within 5 weeks to subject them to serologic-bacteriologic examinations. It was found that brucella antibodies were detected in the blood of infected fishes after 7 days post-inoculation. The antibody titre was maintained throughout the period of observation. The organism was also recovered from visceral organs of infected fishes. On the other hand, none of control fishes showed any serologic or bacteriologic response. These results suggest that fish could be considered as a suspectable species to brucellosis. Subsequently, further studies are needed to clarify the possible role of fish in the disease transmission.