Susceptibility of 46 provenances belonging to 16 species of Eucalyptus to Cylindrocladium leaf blight caused by Cylindrocladium quinqueseptatum, C. clavatum and C. ilicicola differed significantly in detached leaf inoculations. Generally, susceptibility of a provenance to the three species of Cylindrocladium showed significant differences; only a few provenances gave either equally resistant or susceptible reactions to all the three species. C. clavatum was the most virulent species, C. ilicicola the least and C. quinqueseptatum intermediate. Copyright {\textcopyright} 1992, Wiley Blackwell. All rights reserved