Pathogenicity of 206 isolates of Alternaria spp. to apple fruit was determinet. The fungi were isolated from various apple tree organs: young and old leaves (May, November), flowers, flower buds, fruitlets, the skin of fully ripe apples, flower residues on fruits, twigs and cortex. The following fungi were isolated: A. alternata, A. tenuissima and A. consortiale. A. alternata was the most common and the highest number of isolates was pathogenic to apples.