The complement system plays a vital role in preventing life-threatening infections by ensuring optimal functioning of the host immune system. Its dysregulation has been implicated in causing glomerular, hematological, and transplant-related disorders. Eculizumab a novel monoclonal antibody against complement component C5 has emerged in the recent past as the standard of care offering an effective rescue and maintenance therapy against many of these disorders. Its use has been associated with increased risk of infections predominantly with encapsulated organisms. There is no data in the literature on its effects in end-stage kidney disease (ESKD) or dialysis patients. We describe here a very rare case of Aspergillus Niger peritonitis in an ESKD patient on peritoneal dialysis (PD) receiving maintenance eculizumab therapy for atypical hemolytic uremic syndrome. Given that murine models with the same defect as that induced by eculizumab is vulnerable to invasive Aspergillosis, it is suggested that the fungal peritonitis in this patient was the result of the eculizumab therapy.