INTRODUCTION AND IMPORTANCE: Extrarenal calyx (ERC) is very rare upper urinary tract anomaly originally described by Eisendrath in 1925. This malformation usually has major calyces and the renal pelvis located outside the renal parenchyma. Since the incidence of this anomaly is quite low and the clinical presentation is very variable, a high degree of suspicion should be kept in mind to safeguard against inadvertent injury of the calyces when operating on a well-functioning kidney. CASE PRESENTATION: We present here a 41 years old female patient who had right-side flank pain of 2 years duration. Physical examination was unremarkable. Imaging showed a right simple Para-pelvic renal cyst with two renal stones. Open cyst deroofing was done. Intraoperatively the pelvis along with the infundibula was found outside the renal parenchyma and stone was removed from extra renal pelvis and infundibula. The patient was discharged home on 4th post-operative day with smooth post-operative course. Six weeks after the operation, her renal function test was normal and abdomino-pelvic ultrasound examination was found unremarkable. CLINICAL DISCUSSION: ERCs are a rare urinary tract anomaly, described as the presence of a major calyx (or calyces) and renal pelvis outside the kidney parenchyma. This malformation can have complex radiological findings or can cause intraoperative dilemma. CONCLUSION: An extra renal calyx (ERC), described as rare urologic anatomic variations, occurs when the major calyces are located outside of the renal parenchyma. Such rare phenomenon can pose preoperative diagnosis as well as surgical difficulties and high degree of suspicion is the key factor for better outcomes.