Intravesical treatment with various agents is an accepted standard for treating patients with non-muscle-invasive bladder cancer; all guidelines recommend its use. Depending on the agent and the instillation schedule, a reduction in recurrence and a decrease in the progression rate can be achieved.However, many of the recommendations in the various guidelines are currently under debate. Early instillation with a chemotherapeutic agent is probably overtreatment in patients requiring further induction or maintenance therapy because it adds no further benefit. The economic aspects of early instillations are also being discussed. Recent studies question the ability of bacillus Calmette-Guérin (BCG) instillations to reduce the progression of non-muscle-invasive bladder cancer. Furthermore, the superiority of maintenance therapies compared with induction schedules is under debate.There is a great body of evidence that the effectiveness of intravesical chemotherapy can be increased by simple measures. Reduction of BCG side effects without compromising the oncological outcome is possible.