Abstract Aims The aim of this work was to evaluate the efficacy of an organosilicon-based, commercially available antimicrobial formulation in the My-shield® product line against bacterial surface contamination. Methods and results The antimicrobial product was tested in vitro for its long-term persistence on surfaces and effectiveness against Staphylococcus aureus biofilms in comparison to 70% ethanol and 0.1% or 0.6% sodium hypochlorite. Field testing was also conducted over 6 weeks at a university athletic facility. In vitro studies demonstrated the log reductions achieved by the test product, 70% ethanol, and 0.1% sodium hypochlorite were 3.6, 3.1, and 3.2, respectively. The test product persisted on surfaces after washing and scrubbing, and pre-treatment with this product prevented S. aureus surface colonization for up to 30 days. In comparison, pre-treatment with 70% ethanol or 0.6% sodium hypochlorite was not protective against S. aureus biofilm formation after seven days. The field test demonstrated that weekly applications of the test product were more effective at reducing surface bacterial load than daily applications of a control product. Conclusions The test product conferred greater long-term protection against bacterial growth and biofilm formation by S. aureus than ethanol and sodium hypochlorite. Even with less frequent applications, the test product maintained a high level of antimicrobial activity.