Surgical orthotopic implantation (SOI) of histologically intact human RT-4 bladder tumor tissue in nude mice resulted in local growth, invasion, regional extension and metastases as well as distant metastases to other organ sites and lymph nodes, thus mimicking the bladder cancer patient. This metastatic bladder tumor animal model was treated with two doses of new platinum analog ¿Pt(cis-dach)(DPPE).2NO3¿ for the evaluation of antimetastatic efficacy compared to two doses of cisplatinum. Unlike the untreated control group or the group treated with the low dose of cisplatinum, there were no metastases in either the high or low-dose platinum-analog-treated groups and the high-dose cisplatinum-treated group. The results obtained with this patient-like nude-mouse model of bladder cancer indicate that the new platinum analog appears to be a valuable lead compound with antimetastatic efficacy and clinical potential.