Contamination of medicinal plant mass with mycobiots is one of the negative factors deteriorating the quality of raw material. In order to evaluate the impact of the yield processing technologies upon the changes of mycobiots in raw material, the mycobiotic conditions of herb hyssop (Hyssopus officinalis L.) raw material were evaluated under various regimes of active ventilation and optimization of the drying parameters. The impact of ventilation intensity and temperature of drying agent upon the changes and abundance of mycobiota species in medicinal raw material was determined. Irrespective of the temperature of the airflow, the strongest suppressive effect upon the mycobiotic contamination in Hyssopi herba was produced by the 5,000 m³ x (t x h)(-1) airflow. Analysis of the isolated fungi revealed the prevalence of Penicillium, Aspergillus, Alternaria, Cladosporium, Mucor, Rhizopus species in the raw material. In separate samples Botrytis cinerea, Sclerotinia sclerotiorum, Aureobasidium pullulans, Chrysosporium merdarium, Cladorrhinum foecundissimum, Ulocladium consortiale, Trichoderma hamatum, T. harzianum, Gilmaniella humicola, Talaromyces flavus, Rhizomucor pusillus, Hansfordia ovalispora, Verticicladium trifi dum, Trichosporiella cerebriformis micromycetes were also rather abundant. Detection of the above-mentioned micromycetes in herb hyssop samples differed, and partially depended upon the medium used for their isolation.