Typically the fungus Thielaviopsis basicola, the casual organism for black root rot, is generally considered to be widespread in both cultivated and uncultivated soils; surveys were conducted in the catchments surrounding cotton properties to determine if this was the case for Australia. Knowledge of the origin and distribution of soilborne diseases can make significant impacts on both the choice and effectiveness of control measures implemented. If T. basicola had been endemic as suggested by overseas studies, then the lack of commercially effective control measures would Give little hope for control of the disease in cotton in the near future. As it stands this research has shown that T. basicolo only occasionally occurs (in highly disturbed sites) outside of cultivated cotton land, meaning that there is potential to controlthe spread of disease to unaffected farms and fields through the implementation of appropriate farm hygiene measures.