Extradermal melanotic lesions are found predominantly in the oral cavity, colon or conjunctiva, and by far less frequently in other organs. We report for the first time a case of solitary melanosis of the urinary bladder with a follow-up of more than 10 years.A 48-year old man presented with symptoms of frequency, urge incontinence, obstructive voiding symptoms and nocturia. On urethrocystoscopy under general anaesthesia, melanosis of the bladder with visibly reduced bladder capacity was diagnosed and confirmed on biopsy. The patient was treated for his micturation problems with alpha-blockers, intravesical electrostimulation and GAG-substitution therapy, without success. The chronic progression of bladder symptoms and shrinkage eventually led to cystoprostatectomy and bladder replacement by an orthotopic ileal neobladder, 10 years after primary diagnosis.The very low number of reported cases accounts for the lack of management guidelines for this disease. Symptomatic treatment as well as repeated cystoscopic monitoring are logical therapeutic recommendations. Since the development of malignant disease can only be ruled out microscopically, repeated biopsies or prophylactic cystectomy need to be considered.