Pharyngitis and acute cough are common symptoms of URTI (Upper Respiratory Tract Infection) that cause significant distress to sufferers. Herbal medicines such as P. lanceolata are commonly used to address these symptoms but research into their mechanism of action is limited. Any anti-bacterial effect of P. lanceolata is also unknown but may be of benefit to URTI patients.To asses the impact of a syrup containing P. lancolata on the growth and adhesion of a common URTI causing bacteria (S. pyogenes) in an in vitro model.Streptococcus pyogenes Rosenbach was purchased from Culture Collections, UK Health Security Agency (Salisbury, UK). Each well of a sterile flat-bottomed 96-well microtiter plates contained 10 µL of the Plantago lanceolata extract syrup concentrations together with 190 µL of Streptococcus pyogenes inoculum (5 × 103 CFU/mL). The plate was then incubated for 16 h. After incubation, antibacterial activity was evaluated with the BacTiter-Glo™ microbial cell viability assay (Promega). Luminescence was measured with a microplate reader. Bacteria in mid-log phase were grown in Brain Heart Infusion Agar at 37°C overnight and washed three times with PBS. BEAS-2B cells were treated with non-toxic concentrations of Plantago lanceolata extract syrup (12.5, 25 and 50 µg/mL) for 1 h, followed by washing with PBS. Control cells were treated with sterile water. Streptococcus pyogenes (1 x 106) were incubated in Hanks’ balanced salt solution/1% foetal bovine serum for 1 h and added to a 96-well plate containing BEAS-2B cells. After 1 h incubation with gentle shaking, BEAS-2B cells were washed with PBS to remove unbound bacteria. Luciferin (12.5 μM) was added to the cells, and luminescence measured.P.Lanceolata syrup  at concentrations of 12, 25 & 50 ug/ml significantly (P=<0.05- determined by one-way ANOVA) reduced  S.Pyogenes growth and adhesion, vs control.These results demonstrate a novel mechanism of action for P. lanceolata suggesting that this preparation may be able to prevent the adhesion and growth of URTI causing bacteria.The in vitro data is novel and suggest that the benefit of using P. lanceolata may go beyond simple symptomatic relief and could provide benefit to patients at risk of bacterial URTI.