Objective: The drug use-results survey of Metronidazole gel (Rozex® gel 0.75%: hereinafter, this is called “this medicine”) was conducted for the purpose of assessing the safety and effectiveness of this medicine in clinical practice including long-term use. Methods: Patients who initiated treatment with this medicine for sterilization and reduction of odor at cancerous skin ulcer for the first time were registered by the central registration method. The longest period of observation was 1 year. Results: The safety analysis set included 301 patients. The incidence proportion of adverse drug reaction was 3.32% (in 10 of 301 patients), with no serious events. The overall improvement rate was 73.7% (in 205 of 278 patients). At the final observation, the improvement rate of odor by physician's assessment was 80.2% (in 203 of 253 patients) and the improvement rate of patient's satisfaction was 70.1% (in 82 of 117 patients), respectively. Conclusion: The present study demonstrated that this medicine is safe and effective for sterilization and reduction of odor at cancerous skin ulcer, and leads to high treatment satisfaction of patients.