OBJECTIVES: Effective training methods and learning curve (LC) assessment are crucial for more difficult endoscopic procedures. The present study sought to assess the LC of flexible ureteroscopes (fURS) for thulium fiber laser (TFL) lithotripsy and determine the effectiveness of using a porcine kidney model in training modality, to inform future training. METHODS: Postgraduate medical students without experience in ureteroscopy were recruited, and surgical data were collected from 10 consecutive flexible ureteroscopic lithotripsy (fURL) procedures performed on our homemade porcine kidney training model. Cumulative sum (CUSUM) analysis and pooled mean CUSUM curves were applied to determine the LC turning points (TPs), and pre-LC and post-LC data were compared with that of an experienced attending physician. RESULTS: Data from 110 surgeries were included in the analysis. The mean number of surgical units to overcome the LC for the duration of fURS TFL lithotripsy was 4. The operation time, number of tissue damage, and number of central visual shifts were significantly lower in students after the TP than before. No statistically significant difference in operation time was found between the students after the LC (817.50 [703.75-964.75]) and the surgeon group (732.50 [51.00-822.25]). CONCLUSION: Overcoming the LC of fURS TFL lithotripsy requires four surgeries, and the developed ex vivo porcine kidney is a conveniently accessible and effective clinical training model.