Study of the therapeutic effectiveness of ''Abies-masti'', a medication based on Siberian fir needles, in the treatment of subclinical mastitis in cows. The therapeutic effectiveness of the medication was studied in cows with subclinical mastitis. ''Abies-masti'' was rubbed into the skin of the inflamed lobes twice a day after milking until the clinical recovery of the cows. Hematological blood tests, as well as the examination of milk samples from the affected parts of the udder before the treatment and in 5 and 12 days from the beginning of the treatment were carried out according to the methods generally accepted in veterinary practice. The authors of the research established that when using the medication ''Abiesmasti'' to treat cows with subclinical mustitis, the clinical recovery of animals under production conditions was achieved within 3.14 ± 0.26 days. The therapeutic effectiveness of ''Abies-masti'' was 91.4-92.6%. The authors proved that the normalization of the hematological parameters, as well as the organoleptic, physico-chemical, and microbiological indicators of milk occurs on the 5th day from the beginning of the treatment. The cost of the treatment amounted to $ 0.45 per animal. The restoration of the functional state of the mammary gland and the recovery of cows with the use of the given phytomedication is achieved within a shorter period than with the help of other anti-mastitis medications. 48 hours after the last application of the medication, the milk of the recovered animals fully meets the requirements of GOST. The result is achieved thanks to the composition of the medication and the properties of its components, which have a bactericidal effect against the causative agent, increase the protective forces of the macroorganism and ensure the stability of the therapeutic effect. The authors of the research prove the effectiveness and expediency of using this medication based on Siberian fir needles for the treatment of subclinical mastitis in cows.