The external preparation Metronidazole (MTZ) is reported to be useful in controlling the malodor associated with advanced and recurrent breast cancer patients. We prepared two different MTZ external preparations, a 1% MTZ Hydrophilic Ointment and a 0.8% MTZ Carbopol Gel. These preparations were then used to control malodor associated with breast cancer and the results were clinically evaluated. Malodor disappeared within 1 week of administration of either preparation and no adverse reactions were observed. These MTZ external preparations were thus found to be useful in the elimination of malodor as part of the treatment of those patients with advanced and recurrent breast cancer.