Anatomical structures with similar appearance may at times be confused for each other. This situation can be compounded by lack of normal anatomical planes. We did ureterocalicostomy on a 32-year-female with secondary pelvi-ureteral junction obstruction. Post-operatively, it was discovered that she had a long appendix running parallel to ureter in retroperitoneum, which was misidentified as ureter and anastomosed to the lower pole of the kidney. She was re-explored, appendix was removed, ureter was identified and ureterocalicostomy was done. Patient is asymptomatic at 1 year follow-up.
Keywords: Appendicocalicostomy; appendix; ureter; ureterocalicostomy.