The objective of the current study was to examine the diversity of Corylus avellana by its leaf morphology applying the image analysis and elliptic Fourier descriptors and to facilitate identification of the genetic diversity of the species. The stress was laid on the analysis of leaf shape, which is relatively constant and could be used as a morphological marker to recognize different genotypes. The results of the study of seven populations sampled across Lithuania showed strong correlation between leaf size and perimeter (r=0.931, <0.05). Principal component (PC) analysis of normalized elliptic Fourier descriptors (EFD) indicated that the first five PCs stand for about 79 % variation of leaf shape with the PC1 (leaf aspect ratio) responsible for 40 % variation. The EFD method is an effective tool for the evaluation of shape variation of plant leaves, particularly those having no clearly expressed landmarks.