Chronic cystitis associated with ketamine use is a growing problem among a young patient population who use the drug recreationally. Patients may present with symptoms such as urinary frequency, dysuria, urgency and haematuria in accident and emergency departments, GP surgeries, urology outpatient departments, drug rehabilitation or substance misuse units, genitourinary medicine clinics or continence services. Nurses in these areas therefore need to be aware of the symptoms associated with ketamine-associated bladder damage and be prepared to ask patients about recreational drug use and inform them of possible treatments. This case report illustrates one patient's successful response to treatment with chondroitin sulphate 0.2% (Gepan) over a 1-year period.