Brucella peritonitis is a rare infection in patients undergoing peritoneal dialysis, caused by the bacterium Brucella. In a retrospective study of three patients aged 36, 40 and 50 years, who had contact with animals or drank raw milk, presented with abdominal pain and distension without fever. Laboratory tests showed a low blood leukocyte count, elevated C-reactive protein levels, and mildly elevated procalcitonin. The peritoneal effusion had more than 100 leukocytes per mm³ with a predominance of mononuclear cells. The diagnosis was confirmed by Brucella culture from the peritoneal fluid. Treatment consisted of a combination of doxycycline and rifampicin for a minimum of 6 weeks, which resulted in resolution of symptoms without the need to remove the dialysis catheter [Case Report].