Aim of the thesis was to analyse tree damages in selected avenues of municipality of Ljubljana and to compare them with the condition from the year 1999. Three tree avenues were analysed (Prule - Grudnovo nabrežje, Eipprova and Poljanski nasip) by adjusted visual crown assessment method and by estimation of mechanical wounds on trees. Total of 198 trees were describedand compared. 117 of them were horse chestnut (Aesculus hippocastanum L.), 47 Norway maple (Acer platanoides L.), 18 'Globosum' Norway maple (Acer platanoides ćGlobosumć) and smaller number of other tree species. Mechanical wounds are present on all trees, especially on the stem and in the crown of trees. Most of trees have poor vitality. The predominating measures among recommended ones are: branch and crown thinning (31 %) and orderly tree care (30 %) with stump and dead branches removal and thinning around electrical wires. Comparison with the condition from year 1999 showed increased measure of crown thinning (11 %) and orderly tree care (12 %). By adaptation of modern arboricultural measurements the current condition of trees could be essentially improved.