Mastitis is a disease defined as inflamation of the mammary gland, which is common in dairy farms and negatively affects yield and quality. Herbal medicines have gained importance in our country due to lower toxicity, less side effects and absence of residue in milk. This study was conducted on the essential oils obtained by extraction of Ocimum sanctum and Origanum onites, which are medicinal plants against mastitis pathogens. The aim of the study was to investigate the effect of O. sanctum and O. onites on the number of somatic cells, which is an indicator of subclinical mastitis. In the study, 18 dairy cattle and 6 control cows were selected by CMT (California mastitis test) in 80 dairy cows farm. The solution prepared from essential oils obtained from O. sanctum and O.onites plants was applied to the sick udder of 18 cows with subclinical mastitis, 12 ml / day x 3 days, 1st, 5th, 9th, 26th days. SHS was determined by taking the sample. SHS was measured as 2185.78 cells / ml before solution application and 809.72 cells / ml after solution applications. In conclusion, intramamarian administration of O. sanctum and O.onites in the treatment of subclinical mastitis can be considered as an alternative or an addition to antibiotics.