The study was conducted during the 2009-2010 period in three villages in the Kardzhali region. A total of 820.0 dka of oriental tobacco were investigated, grown under different soil and climatic conditions and under different farming practices. It was found, that the weeds associations in the monitored tobacco fields were not characterized by great diversity of weed species. Late spring species dominated the annual weeds group: Chenopodium album L., Portulaca oleracea L., Amaranthus retroflexus L. Echinochloa crus galli (Stev) Koss, followed by some perennial types: Cynodon dactylon (L.) Pers, Sorghum halepensis (L.) Pers., Convolvulus arvensis L., Cirsium arvense (L.) Skop. and Euphorbia cyparissias L.. The two species of the root parasite broom-rape (Orobanche muteli Schultz and Orobanche ramoza L.) were found in the investigated areas which can be explained by the monoculture cultivation of tobacco on infested soils. The monitoring demonstrated the presence of a stem parasite Cuscuta epithymum Weiche.