RESUMEN
An unusual case of peritonitis in a 61-year-old patient is reported where culture for bacteria and fungi were negative. Acanthamoeba was isolated and the patient was treated with Ceftazidine, Cefazolin, Levofloxacin, Fluconazole and Rifampicin with regular haemodialytic support. The patient was completely cured of the infection and continuous ambulatory peritoneal dialysis (CAPD) fluid became clear after 2 weeks of treatment. Diagnosis and treatment of Acanthamoeba infections are difficult due to the rarity of the infections, lack of familiarity of most clinicians with disease syndromes, and limitations of therapeutics options. Even an experienced microbiologist can easily mistake the amoebae in ascitic fluid for peritoneal macrophages or lymphocytes.