Research was carried out on European filbert (C. avellana L.) growing wild in eastern Serbia with particular stress laid on fertility potential and nut properties in dependence on number in inflorescence. Frequently, there are two nuts joined in cluster (42.1%) and single nut (35.0%). Size and weight of both nuts and kernel are reduced by number in inflorescence increase. Both mineral substances and crude proteins contents are decreased. Oil contents in kernel is in converse proportion to crude proteins contents.