The intravesical delivering of chemotherapy remains, up today, partially empirical and the pharmacokinetics poorly understood. Some Authors indicate that a higher response rate can be obtained optimizing intravesical chemotherapy A number of different strategies to deliver an effective therapeutic tumor dose are currently being explored. Drug concentration is of primary importance in delivering effective intravesical chemotherapy. The optimum dose/concentration should be defined for each individual treatment. Another important variable is the period of exposure. The dwell time of intravesical chemotherapy has received little attention and it is still object of debate. Diffusion of an intravesical chemotherapeutic agent also depends on its molecular weight and lipid solubility. Controversy still remains about volume of the instillate. A marked influence of pH solution on drug activity has been demonstrated. Several patients' factors influencing the outcome of intravesical chemotherapy must be taken into account. The main actions that can be adopted to optimize intravesical chemotherapy are illustrated. Increasing the dose and the concentration, increasing the volume of instillate and minimizing the volume of residual urine at the time of treatment, reducing urine production before and during treatment by voluntary dehydration, alkalinizing the urine by use of oral sodium bicarbonate or adopting buffered solution at alkaline pH, particularly for doxorubicin and epirubicina and empting the bladder at the end of the treatment in presence of vesico-ureteral reflux or post-voiding residue, are the best actions that can be suggested, at the present time, to optimize intravesical chemotherapy.