BACKGROUND: To our knowledge, no previous case report explicitly shows that urethral catheter misplacement in the vagina cannot be ruled out even if urinary outflow is observed during catheterization. CASE PRESENTATION: A 70-year-old female underwent urethral catheterization during induction of general anesthesia for hemiarthroplasty using a bipolar hip prosthesis. Although the urethral meatus could not be visualized, urinary outflow was observed. However, drainage subsequently stopped, and the catheter was eventually found to have been misplaced in the vagina. Detection of the catheter misplacement was delayed because of the assumption that no urinary outflow occurs when the catheter is misplaced in the vagina. CONCLUSION: Even if urinary outflow is observed during female urethral catheterization, catheter misplacement in the vagina cannot be ruled out
therefore, catheter misplacement in the vagina must be verified in patients for whom the urethral meatus cannot be identified for catheter insertion or when drainage stops.