Basidiobolus ranarum is an environmental saprophytic fungus which is found across the globe, predominantly in the regions with arid climate. It resides in the intestine of amphibians, fishes, and insectivorous bats and can be found in the soil also. Inoculation of this pathogen in an open wound or after a trivial trauma or insect bite is a proposed mechanism of its infection in humans. It is a potentially pathogenic fungus that usually leads to chronic subcutaneous swelling in immunocompetent individuals; intra-abdominal extension of this infection is extremely rare. Even in abdominal basidiobolomycosis, description of few cases of bowel wall thickening and intra-abdominal masses is there. However, presentation of basidiobolomycosis as retroperitoneal fibrosis has never been reported till date. A 19-year-old female presented in our emergency block with anasarca, anuria, and right-sided flank pain since 3 days. She had thickening with induration and discoloration of the skin over the abdominal and chest wall on right side. An ultrasound followed by MRI was done; which revealed mild right-sided hydronephrosis with a large T2W hypointense mass in abdomen (involving the right kidney, perinephric space, retroperitoneum, and right adnexa). Biopsy was taken from the abdominal mass which came out to be Basidiobolomycosis. We, herein report an extremely rare case of abdominal basidiobolomycosis, presenting with renal involvement and secondary retroperitoneal fibrosis along with intra-abdominal masses which has never been reported till date.