RATIONALE:: There are already several reports concerning the occurrence of urethral diverticulum (UD) in female patients, but only rarely has a article describing UD combined with UD calculi or squamous carcinoma been published. Moreover, a case with squamous carcinoma and UD calculi at the same time has never been reported, making this the first case report about this condition. PATIENT CONCERNS:: A 43-year-old woman presented to the gynaecology department with a complaint of a hard mass beneath the anterior vaginal wall. DIAGNOSES:: Transvaginal ultrasound (TVU) revealed a UD. INTERVENTIONS:: We performed a standard urethral diverticular excision. Intraoperatively, we identified and removed a stone from the diverticulum. The intraoperative finding of a stone challenged the diagnosis of UD, with subsequent histological examination of biopsy tissue from the mass demonstrating broadly squamous metaplasia. OUTCOMES:: The broadly squamous metaplasia predominantly originated from the stone, and the stone was entirely removed. No complications occurred during the whole follow-up period. Moreover, after the 12-month follow-up, there was no diverticular recurrence or carcinoma metastasis. LESSONS:: UD calculi may be considered a risk factor for female urethra squamous metaplasia, which with the potential of squamous carcinoma, so patients will be advised to treat this condition immediately.