Peritonitis is a common problem in patients undergoing peritoneal dialysis. However, peritonitis due to Cunninghamella (C.) bertholletiae, a fungus of the class Zygomycetes, is rare. We present a case of fungal peritonitis in a patient on continuous ambulatory peritoneal dialysis due to kidney rejection. Direct examination of the patient's peritoneal fluid showed fungal hyphae, and the culture was identified as C. bertholletiae. A cumulative dose of 1,600 mg fluconazole was given to the patient intraperitoneally over a one-week period. When his condition had stabilised, oral antifungal treatment was administered for two weeks. After removal of the Tenckhoff catheter, the patient was discharged with arteriovenous fistulation for haemodialysis. Zygomycosis due to C. bertholletiae is often fatal and non-responsive to systemic antifungal therapy. This case is the first from India with a successful outcome, and highlights the importance of early detection and intervention for successful outcome of peritonitis caused by C. bertholletiae.