A 52-year-old man on peritoneal dialysis noticed brownish particles in his dialysis catheter. Doctors identified the particles as a rare fungus called Eidernor doerrieniae, which had never been found in humans before. Although the patient had no symptoms, doctors immediately removed the catheter and treated him with antifungal medications, which successfully cured the infection. This case shows why patients and doctors should take visible particles in dialysis catheters seriously, even when there are no obvious signs of infection.