Aims: The aim of this study is to prepare herbal gargle preformulations making use of essential oil of aerial parts of Thymus capitatus growing wild in Northern Cyprus and comparing antimicrobial efficacy between these formulations with pure essential oil. Place and Duration of Study: Department of Pharmaceutical Technology, Faculty of Pharmacy, Near East University, Nicosia, TRNC and Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Ankara University, Ankara, Turkey, between January 2017 and June 2017. Methodology: Preformulations with three different concentrations of Thymus capitatus essential oil were prepared by using simple preparation method. Preformulation studies were done in lab with less than 500 ml. There is not specific process parameters. Manufacturing process and process parameters will be clarified with further studies. These compositions and the essential oil were tested in-vitro for antimicrobial activity studies by using broth microdilution method. Staphylococcus aureus ATCC 43300, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae RSKK 574, Salmonella paratyphi C, Pseudomonas aeruginosa ATCC 9027, Pseudomonas aeruginosa ATCC 27853 as bacteria and Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 as yeasts were used for antimicrobial activity tests. Results: All trials were found to be more effective than EO, and a significant effect was observed when compared to the values ​​of standard antimicrobial agents. Conclusion: TheThymus capitatus growing in Northern Cyprus could be used as a herbal raw material, essential oil source in developing herbal gargle preformulations to reduce fungal and bacterial infections in mouth.