Resumo. ABSTRACTEucalyptus benthamiiis one of the planted forest species in Southern Brazil due to its frost resistance.The main disease in commercial plantations is the leaf spot caused byCylindrocladiumcandelabrum.The objective of this work was to evaluate incidence and severity of this disease inEucalyptusbenthamiiplantations, in Rio Negrinho, SC state. The survey was performed in three plantations (4, 8 and 18 months-old), quantifying the number of diseased trees and evaluating the severity by using a diagrammatic scalevarying from 0 (no spot and shedding of leaves) to 5 (more than 75 % of defoliation). Four evaluationswere done from July/2011 to June/2013. The average incidence of leaf spot on trees varied from 2.6 to43.8 %, depending upon the age, while the average severity varied from 1.2 to 2.8, with low severity intrees of 4 and 8 months-old. It was verified increase on disease severity increasing tree age and the directrelationship between disease intensity and precipitation volume as well as between severity and tree height.The relationship between the incidence of plants with leaf spot varied according to tree heights.