摘要： Introduction Urothelial bladder carcinoma frequently occurs in adults over 60?years of age; yet it affects only 0.1–0.4% of patients before the first 2?decades of life. We present two cases of transitional cell carcinoma in two young patients treated with holmium:YAG laser to demonstrate the effectiveness of this technique in pediatrics. Cases and methods Case study 1 During a routine abdomen ultrasound, a 14-year-old female showed a endoluminal formation about 10 × 6 × 10?mm of size, in the left paramedian site. There was an absence of meaningful vascular signs during color-Doppler. Physical examination and laboratory exams were all normal. Case study 2 A 12-year-old female presented with acute macroscopic haematuria. No other symptoms were associated. Bladder ultrasound revealed an irregular 15?mm intravesical endophytic lesion in the posterior-superior area. In both cases, treatment commenced with an en bloc enucleation. For the resections, a 272?μm holmium:YAG fiber laser was used through the 12 Ch cystoscopy working channel with an energy of 0.8–1?J/pulse and a frequency of 8–10?Hz. Results There was no haematuria after the procedure and the transurethral catheter remained for 12?h. The histological diagnosis was papillary urothelial neoplasm of low malignant potential. Cystoscopy was performed 3 and 9?months after the surgery and an ultrasound every 6?months, which all came back normal. The follow-up continued for each patient with a cystoscopy once a year, according to EAU guidelines. Conclusion Based on the findings, holmium:YAG laser is a good alternative to treat superficial transitional cell carcinoma in pediatric patients.