Intravesical instillation of Adriamycin® has successfully been used in the treatment of bladder tumours. The Adriamycin concentration in the bladder has been monitored and the area under the bladder concentration-time curve, AUC, is proposed to be considered rather than the amount of instilled drug when optimizing the treatment schedules. pH effects which may arise in the bladder when instilling protolytic drugs like Adriamycin are discussed.