The objective of this study was to estimate the ability of a thermophilic fungus Thermomyces lanuginosus (syn. Humicola lanuginosa) to biosynthesize lipolytic enzymes. The material investigated consisted of 144 strains of this fungus that was isolated from various sources: mushroom compost, garden compost, leaf compost, biohumus, hazelnuts, and raw coffee beans. The strains were incubated at 55°C on a solid medium containing 1.5% of sunflower oil. The study proved that all tested strains were able to hydrolyze the sunflower oil contained in the medium. The strains isolated from the biohumus and raw coffee beans showed the highest lipolytic activity whereas the strains isolated from the leaf compost and shelled hazelnuts had the lowest lipolytic activity. As for the strains showing the highest lipolytic activity, a significantly negative correlation between the diameters of their colonies and their lipolytic activity was stated.