Increased incidence of leaf spots on many tree species, up to the presence of peripheral importance only, including linden trees was noticed recently. First massive and continuous occurence of the fungus Cercospora microsora Sacc. [teleomorph Mycosphaerella millegrana (Cook.) Schröet., Mycosphaerella microsora Syd.], causal agent of anthracnose on linden trees (Tilia cordata Mill.) grown in urban plantings in Slovakia was reported. Along with this, certain of the important growth characteristics of this fungus were studied under laboratory conditions. To specify Cercospora biology mycelial growth of C. microsora in pure hyphal cultures was observed in relation to medium and locality. One-way ANOVA has confirmed a statistically significant influence of both factors, culture medium and locality on growth rate values of C. microsora. The effect of these factors has not proved unambiguously in all cases. In the case of one locality (Nitra), the significant influence of used media has not been proved (P > 0.05). PDAg showed generally as the most suitable medium, inducing the most intensive growth in three localities (41.06 mm/week on average). Comparing three localities, the effect of this factor is not so unambiguous. Growth rate values from the localities Bratislava and Pribeta indicate unsuitability of medium A for the fast radial growth. A Tukey test separately conducted for the factors medium and the locality revealed the significant combinations of means (P ≤ 0.05).