Endocervicosis/ endosalpingiosis of the bladder is a very rare benign condition, with a total of 34 documented cases found in the literature. Herein, we report a 35-year-old woman with suspected bladder cancer following a cystoscopic examination, which revealed a mass on the right posterior bladder wall. Transurethral resection of the lesion was performed, and both pathological and immunohistochemical findings confirmed a diagnosis of endocervicosis/ endosalpingiosis. Recurrence was seen 6 months later in a follow-up cystoscopic examination and a partial cystectomy was performed. Since endocervicosis/ endosalpingiosis tends to recur, a partial cystectomy is the best therapeutic option for patients with persistent symptoms or recurrence.