Approximately 70-80% of bladder cancers are superficial tumors and not muscle invasive. Complete transurethral resection of the bladder tumour (TUR-BT) is the standard approach to these patients. Intravesical treatments such as adriamycin, doxorubicin, epirubicin, mitomycin-c and Bacillus Calmette-Guerin (BCG) may be performed after TUR-BT in order to prevent further recurrence or progression. BCG is generally used in high-risk patients and causes local or systemic side effects in less than 5% of patients. Osteoarticular side effects are very rare and usually manifest as joint pain and arthritis (%0.5-1). In this case report, we present the management of reactive arthritis in a patient treated with intravesical BCG for bladder cancer.