Low pH, hydrogen peroxide generation, and the hyperosmolarity mechanisms of antimicrobial action are the same for all honeys. Furthermore, Mānuka honey has been proven to contain high concentrations of methylglyoxal (MGO), causing the relatively superior antimicrobial activity of manuka honey compared to non-MGO honeys. In large amounts, Mānuka honey is successful in killing Staphylococcus aureus biofilms in vitro. Lower concentrations of honey, however, are great for clinical use as a topical rinse in chronic rhinosinusitis in order to maximise the tolerability and ease of the delivery technique. This analysis, therefore, was designed to evaluate the contribution of MGO to the activity of Mānuka honey, and to determine whether the antibiofilm activity of low-dose honey can be augmented by the addition of exogenous MGO.