Patients with malodorous wounds often experience social isolation, depression, shame, embarrassment and poor appetite, all of which can have a negative impact on their quality of life. The healthcare professionals caring for them face difficult clinical challenges in terms of treating the cause and managing the symptoms. This study employed a randomized, placebo-controlled double-blind design to investigate the effectiveness of metronidazole gel on wound malodour, the main focus of this article. In addition, changes in self-report of mood state were also explored. There was a 100% success rate for the metronidazole gel, mostly within 3 days, with no adverse events reported. As there was a 76% success rate in the placebo group, there was no significant difference in success rates between the two groups. Odour ratings given by patients and nurses were significantly correlated (P<0.001). There was no significant difference in mood state between the groups over time. This study provides some evidence to support the use of metronidazole gel in the treatment of patients with malodorous wounds, but indicates the need for further research in this area.